Scheduling uplink transmissions

ABSTRACT

For scheduling transmissions of data channels, control channels, or random access channels using downlink control information (DCI) formats, a DCI format can configure a transmission of one or multiple data channels over respective one or multiple transmission time intervals. A first DCI format can configure the parameters for a channel transmission and a second DCI format can trigger the channel transmission and indicate respective one or more transmission time intervals.

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIMS OF PRIORITY

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 15/452,665 filed Mar. 7, 2017, now U.S. Pat. No.10,568,061, and claims priority to: U.S. Provisional Patent ApplicationNo. 62/310,913 filed on Mar. 21, 2016; U.S. Provisional PatentApplication No. 62/312,033 filed on Mar. 23, 2016; U.S. ProvisionalPatent Application No. 62/313,900 filed on Mar. 28, 2016; U.S.Provisional Patent Application No. 62/330,966 filed on May 3, 2016; andU.S. Provisional Patent Application No. 62/335,353 filed on May 12,2016. The above-identified patent documents are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates generally to wireless communicationsystems and, more specifically, to scheduling transmissions andreceptions of data channels, control channels, or random accesschannels.

BACKGROUND

Wireless communication has been one of the most successful innovationsin modern history. Recently, the number of subscribers to wirelesscommunication services exceeded five billion and continues to growquickly. The demand of wireless data traffic is rapidly increasing dueto the growing popularity among consumers and businesses of smart phonesand other mobile data devices, such as tablets, “note pad” computers,net books, eBook readers, and machine type of devices. In order to meetthe high growth in mobile data traffic and support new applications anddeployments, improvements in radio interface efficiency and coverage isimportant.

SUMMARY

Embodiments of the present disclosure provide methods and apparatus forscheduling transmissions and receptions of data channels, controlchannels, or random access channels.

In a first embodiment, a UE includes a receiver and a transmitter. Thereceiver is configured to receive a downlink control information (DCI)format that configures transmissions of a number of physical uplink datachannels (PUSCHs) over a number of subframes up to a predeterminedmaximum number of N_(SF) subframes. The DCI format includes a number ofsubframes field that is represented by ┌log₂ (N_(SF))┐ bits andindicates a number n_(SF)≤N_(SF) of subframes for n_(SF) PUSCHtransmissions. The DCI format also includes a timing offset field thatincludes a timing offset o_(t) for a subframe of a first of the PUSCHtransmissions that is determined as n+k+o_(t), n is the subframe of theDCI format reception, and k is a minimum number of subframes for a PUSCHtransmission after the DCI format reception. The DCI format furtherincludes a hybrid automatic repeat request (HARQ) process number fieldthat is represented by ┌log₂ (N_(HARQ))┐ bits and indicates a HARQprocess number n_(HARQ) from a total of N_(HARQ) HARQ processes. HARQprocess number n_(HARQ) applies for the first PUSCH transmission, HARQprocess number (n_(HARQ)+j−1)mod N_(HARQ) applies for a j-th of thePUSCH transmissions, and 1<j≤n_(SF). The DCI format additionallyincludes a new data indicator (NDI) field that is represented by N_(SF)bits and indicates whether a PUSCH transmission, from the n_(SF) PUSCHtransmissions, conveys a new data transport block (TB) or aretransmission of a data TB. ┌ ┐ is a ceiling function that rounds anumber to its immediately next larger integer and log₂(x) is a logarithmfunction with base 2 resulting a logarithm with base 2 for number x. Thetransmitter is configured to transmit the n_(SF) PUSCH transmissionsover the n_(SF) subframes.

In a second embodiment, a base station includes a transmitter and areceiver. The transmitter is configured to transmit a DCI format thatconfigures transmissions of a number of PUSCHs over a number ofsubframes up to a predetermined maximum number of N_(SF) subframes. TheDCI format includes a number of subframes field that is represented by┌log₂(N_(SF))┐ bits and indicates a number n_(SF)≤N_(SF) of subframesfor n_(SF) PUSCH transmissions. The DCI format also includes a timingoffset field that includes a timing offset o_(t) for a subframe of afirst of the PUSCH transmissions that is determined as n+k+o_(t), n isthe subframe of the DCI format reception, and k is a minimum number ofsubframes for a PUSCH transmission after a DCI format reception. The DCIformat further includes a HARQ process number field that is representedby ┌log₂ (N_(HARQ))┐ bits and indicates a HARQ process number n_(HARQ)from a total of N_(HARQ) HARQ processes. HARQ process number n_(HARQ)applies for the first PUSCH transmission, HARQ process number(n_(HARQ)+j−1)mod N_(HARQ) applies for a j-th of the PUSCHtransmissions, and 1<j≤n_(SF). The DCI format additionally includes anew data indicator (NDI) field that is represented by N_(SF) bits andindicates whether a PUSCH transmission, from the n_(SF) PUSCHtransmissions, conveys a new data TB or a retransmission of a data TB. ┌┐ is a ceiling function that rounds a number to its immediately nextlarger integer and log₂(x) is a logarithm function with base 2 resultinga logarithm with base 2 for number x. The receiver is configured toreceive the n_(SF) PUSCH transmissions over the n_(SF) subframes.

In a third embodiment, a UE includes a receiver and a transmitter. Thereceiver is configured to receive a first DCI format in a subframehaving a first index that configures parameters for a transmission of achannel. The receiver is also configured to receive a second DCI formatin a subframe having a second index that triggers the transmission ofthe channel. The transmitter is configured to transmit the channel in asubframe having a third index.

In a fourth embodiment, a base station includes a transmitter and areceiver. The transmitter is configured to transmit a first DCI formatin a subframe having a first index that configures parameters for atransmission of a channel. The transmitter is also configured totransmit a second DCI format in a subframe having a second index thattriggers the transmission of the channel. The receiver is configured toreceive the channel in a subframe having a third index.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless network according to thisdisclosure;

FIGS. 2A and 2B illustrate example wireless transmit and receive pathsaccording to this disclosure;

FIG. 3A illustrates an example user equipment according to thisdisclosure;

FIG. 3B illustrates an example enhanced NodeB (eNB) according to thisdisclosure;

FIG. 4 illustrates an example encoding process for a downlink controlinformation (DCI) format for use with an eNB according to thisdisclosure;

FIG. 5 illustrates an example decoding process for a DCI format for usewith a UE according to this disclosure;

FIG. 6 illustrates an example UL subframe (SF) structure for PUSCHtransmission or PUCCH transmission according to this disclosure;

FIG. 7 illustrates a transmitter block diagram for uplink controlinformation (UCI) and data in a PUSCH according to this disclosure;

FIG. 8 illustrates a receiver block diagram for UCI and data in a PUSCHaccording to this disclosure;

FIG. 9 illustrates a transmission of an UL channel transmission, such asa PUSCH or a PUCCH, over ten RBs interleaved in frequency according tothis disclosure;

FIG. 10 illustrates an example of an allocation of two interlaces withconsecutive indexes for a PUSCH transmission from a first UE and anexample of an allocation of two interlaces with non-consecutive indexesfor a PUSCH transmission from a second UE according to this disclosure;

FIG. 11 illustrates an example of shifting for interlace indexes usedfor multiple PUSCH transmissions from a UE according to this disclosure;

FIG. 12 illustrates an example determination of a HARQ process number incase of multi-SF PUSCH scheduling by an UL grant according to thisdisclosure;

FIG. 13 illustrates an example determination by a UE of a redundancyversion (RV) to apply for a data TB transmission depending on a value ofa new data indicator (NDI) field;

FIG. 14 illustrates an example for multiplexing a number of CSI reportsin a number of PUSCH transmission scheduled by an UL grant according tothis disclosure;

FIG. 15 illustrates an overview of a contention-based random accessprocess according to this disclosure;

FIG. 16 illustrates four examples of PRACH formats according to thisdisclosure;

FIG. 17 illustrates an example for PRACH transmission from a UEaccording to this disclosure;

FIG. 18 illustrates an example for PRACH detection at an eNB accordingto this disclosure;

FIG. 19 is a diagram illustrating a communication using CA according tothis disclosure.

FIG. 20 illustrates repetitions of a PRACH format 4 transmission oversix of the twelve symbols of a SF that includes fourteen symbolsaccording to this disclosure;

FIG. 21 illustrates a first example for a modified PRACH transmissionstructure over 12 SF symbols according to this disclosure;

FIG. 22 illustrates a PRACH transmission with two repetitions in thefrequency domain during a same SF for a PRACH format based on PRACHFormat 0 according to this disclosure;

FIG. 23 illustrates a placement of guard-bands for a PRACH transmissionon an unlicensed cell when the PRACH is transmitted at either or bothedges of a system BW;

FIG. 24 illustrates a mechanism for indicating an SF for a PRACHtransmission according to this disclosure;

FIGS. 25A and 25B illustrate a process for transmitting acontention-free PRACH with multiple transmission opportunities accordingto this disclosure;

FIG. 26 illustrates a process for transmitting a PRACH and an associatedRAR according to this disclosure;

FIGS. 27A and 27B illustrates a size of a RAR message with respect tothe octets used to provide a TA command and an UL grant forcontention-based random access and for contention-free random accessaccording to this disclosure;

FIG. 28 illustrates an example for a determination of a HARQ-ACKcodebook based on DAI fields in DL DCI formats for uplink controlinformation (UCI) cell group (UCG) cells and non-UCG cells according tothis disclosure;

FIG. 29 illustrates an example for a UE to transmit a HARQ-ACK codebookfor UCG cells either in a PUSCH on a UCG cell or on a PUCCH in a(primary cell) PCell;

FIG. 30 illustrates a use of a β_(PUSCH) ^(HARQACK) value fordetermining resources for multiplexing a HARQ-ACK codebook in a numberof scheduled PUSCH transmissions depending on the number of scheduledPUSCH transmission according to this disclosure;

FIG. 31 illustrates a multiplexing of a PUSCH_Tx_ind in a PUSCHtransmission according to this disclosure;

FIG. 32 illustrates a multiplexing of a PUSCH_Tx_ind with HARQ-ACKinformation in a HARQ-ACK codebook according to this disclosure;

FIG. 33 illustrates a transmission of a HARQ-ACK codebook by a UE inresponse to a detection of a DCI format conveying a HARQ-ACK requestaccording to this disclosure; and

FIG. 34 illustrates an example timeline for a transmission of a HARQ-ACKcodebook by a UE according to this disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 34, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the present disclosure. Those skilled inthe art will understand that the principles of the present disclosuremay be implemented in any suitably arranged wireless communicationsystem.

The following documents and standards descriptions are herebyincorporated by reference into the present disclosure as if fully setforth herein:

TS 36.211 v13.1.0, “E-UTRA, Physical channels and modulation” (“REF 1”);3GPP TS 36.212 v13.1.0, “E-UTRA, Multiplexing and Channel coding” (“REF2”), 3GPP TS 36.213 v13.1.0, “E-UTRA, Physical Layer Procedures” (“REF3”); 3GPP TS 36.321 v13.1.0, “E-UTRA, Medium Access Control (MAC)protocol specification” (“REF 4”); 3GPP TS 36.331 v13.1.0, “E-UTRA,Radio Resource Control (RRC) Protocol Specification” (“REF 5”); ETSI EN301 893 V1.7.1, Harmonized European Standard, “Broadband Radio AccessNetworks (BRAN); 5 GHz high performance RLAN” (“REF 6”); and IEEE, “Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)Specifications”, http://standards.ieee.org/getieee802/802.11.html. (“REF7”)

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a ‘Beyond 4G Network’ or a‘Post LTE System.’

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud RadioAccess Networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul, moving network, cooperativecommunication, Coordinated Multi-Points (CoMP), reception-endinterference cancellation and the like.

In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and slidingwindow superposition coding (SWSC) as an advanced coding modulation(ACM), and filter bank multi carrier (FBMC), non-orthogonal multipleaccess (NOMA), and sparse code multiple access (SCMA) as an advancedaccess technology have been developed.

In this disclosure, a UE is also commonly referred to as a terminal or amobile station, can be fixed or mobile, and can be a cellular phone, apersonal computer device, or an automated device. An eNB is generally afixed station and can also be referred to as a base station, an accesspoint, or other equivalent terminology.

FIG. 1 illustrates an example wireless network 100 according to thisdisclosure. The embodiment of the wireless network 100 shown in FIG. 1is for illustration only. Other embodiments of the wireless network 100could be used without departing from the scope of this disclosure.

The wireless network 100 includes an eNodeB (eNB) 101, an eNB 102, andan eNB 103. The eNB 101 communicates with the eNB 102 and the eNB 103.The eNB 101 also communicates with at least one Internet Protocol (IP)network 130, such as the Internet, a proprietary IP network, or otherdata network.

Depending on the network type, other well-known terms may be usedinstead of “eNodeB” or “eNB,” such as “base station” or “access point.”For the sake of convenience, the terms “eNodeB” and “eNB” are used inthis patent document to refer to network infrastructure components thatprovide wireless access to remote terminals. Also, depending on thenetwork type, other well-known terms may be used instead of “userequipment” or “UE,” such as “mobile station,” “subscriber station,”“remote terminal,” “wireless terminal,” or “user device.” For the sakeof convenience, the terms “user equipment” and “UE” are used in thispatent document to refer to remote wireless equipment that wirelesslyaccesses an eNB, whether the UE is a mobile device (such as a mobiletelephone or smartphone) or is normally considered a stationary device(such as a desktop computer or vending machine).

The eNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe eNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business (SB); a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 116, which may be amobile device (M) like a cell phone, a wireless laptop, a wireless PDA,or the like. The eNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe eNB 103. The second plurality of UEs includes the UE 115 and the UE116. In some embodiments, one or more of the eNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, long-termevolution (LTE), LTE-A, WiMAX, or other advanced wireless communicationtechniques.

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with eNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the eNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, one or more of BS 101, BS 102 and BS103 include 2D antenna arrays as described in embodiments of the presentdisclosure. In some embodiments, one or more of BS 101, BS 102 and BS103 support scheduling uplink transmissions and random access inunlicensed carriers.

Although FIG. 1 illustrates one example of a wireless network 100,various changes may be made to FIG. 1. For example, the wireless network100 could include any number of eNBs and any number of UEs in anysuitable arrangement. Also, the eNB 101 could communicate directly withany number of UEs and provide those UEs with wireless broadband accessto the network 130. Similarly, each eNB 102-103 could communicatedirectly with the network 130 and provide UEs with direct wirelessbroadband access to the network 130. Further, the eNB 101, 102, and/or103 could provide access to other or additional external networks, suchas external telephone networks or other types of data networks.

FIGS. 2A and 2B illustrate example wireless transmit and receive pathsaccording to this disclosure. In the following description, a transmitpath 200 may be described as being implemented in an eNB (such as eNB102), while a receive path 250 may be described as being implemented ina UE (such as UE 116). However, it will be understood that the receivepath 250 could be implemented in an eNB and that the transmit path 200could be implemented in a UE. In some embodiments, the receive path 250is configured to support scheduling uplink transmissions and randomaccess in unlicensed carriers.

The transmit path 200 includes a channel coding and modulation block205, a serial-to-parallel (S-to-P) block 210, a size N Inverse FastFourier Transform (IFFT) block 215, a parallel-to-serial (P-to-S) block220, an add cyclic prefix block 225, and an up-converter (UC) 230. Thereceive path 250 includes a down-converter (DC) 255, a remove cyclicprefix block 260, a serial-to-parallel (S-to-P) block 265, a size N FastFourier Transform (FFT) block 270, a parallel-to-serial (P-to-S) block275, and a channel decoding and demodulation block 280.

In the transmit path 200, the channel coding and modulation block 205receives a set of information bits, applies coding (such as alow-density parity check (LDPC) coding), and modulates the input bits(such as with Quadrature Phase Shift Keying (QPSK) or QuadratureAmplitude Modulation (QAM)) to generate a sequence of frequency-domainmodulation symbols. The serial-to-parallel block 210 converts (such asde-multiplexes) the serial modulated symbols to parallel data in orderto generate N parallel symbol streams, where N is the IFFT/FFT size usedin the eNB 102 and the UE 116. The size N IFFT block 215 performs anIFFT operation on the N parallel symbol streams to generate time-domainoutput signals. The parallel-to-serial block 220 converts (such asmultiplexes) the parallel time-domain output symbols from the size NIFFT block 215 in order to generate a serial time-domain signal. The addcyclic prefix block 225 inserts a cyclic prefix to the time-domainsignal. The up-converter 230 modulates (such as up-converts) the outputof the add cyclic prefix block 225 to an RF frequency for transmissionvia a wireless channel. The signal may also be filtered at basebandbefore conversion to the RF frequency.

A transmitted RF signal from the eNB 102 arrives at the UE 116 afterpassing through the wireless channel, and reverse operations to those atthe eNB 102 are performed at the UE 116. The down-converter 255down-converts the received signal to a baseband frequency, and theremove cyclic prefix block 260 removes the cyclic prefix to generate aserial time-domain baseband signal. The serial-to-parallel block 265converts the time-domain baseband signal to parallel time domainsignals. The size N FFT block 270 performs an FFT algorithm to generateN parallel frequency-domain signals. The parallel-to-serial block 275converts the parallel frequency-domain signals to a sequence ofmodulated data symbols. The channel decoding and demodulation block 280demodulates and decodes the modulated symbols to recover the originalinput data stream.

Each of the eNBs 101-103 may implement a transmit path 200 that isanalogous to transmitting in the downlink to UEs 111-116 and mayimplement a receive path 250 that is analogous to receiving in theuplink from UEs 111-116. Similarly, each of UEs 111-116 may implement atransmit path 200 for transmitting in the uplink to eNBs 101-103 and mayimplement a receive path 250 for receiving in the downlink from eNBs101-103.

Each of the components in FIGS. 2A and 2B can be implemented using onlyhardware or using a combination of hardware and software/firmware. As aparticular example, at least some of the components in FIGS. 2A and 2Bmay be implemented in software, while other components may beimplemented by configurable hardware or a mixture of software andconfigurable hardware. For instance, the FFT block 270 and the IFFTblock 215 may be implemented as configurable software algorithms, wherethe value of size N may be modified according to the implementation.

Furthermore, although described as using FFT and IFFT, this is by way ofillustration only and should not be construed to limit the scope of thisdisclosure. Other types of transforms, such as Discrete FourierTransform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions,could be used. It will be appreciated that the value of the variable Nmay be any integer number (such as 1, 2, 3, 4, or the like) for DFT andIDFT functions, while the value of the variable N may be any integernumber that is a power of two (such as 1, 2, 4, 8, 16, or the like) forFFT and IFFT functions.

Although FIGS. 2A and 2B illustrate examples of wireless transmit andreceive paths, various changes may be made to FIGS. 2A and 2B. Forexample, various components in FIGS. 2A and 2B could be combined,further subdivided, or omitted and additional components could be addedaccording to particular needs. Also, FIGS. 2A and 2B are meant toillustrate examples of the types of transmit and receive paths thatcould be used in a wireless network. Any other suitable architecturescould be used to support wireless communications in a wireless network.

FIG. 3A illustrates an example UE 116 according to this disclosure. Theembodiment of the UE 116 illustrated in FIG. 3A is for illustrationonly, and the UEs 111-115 of FIG. 1 could have the same or similarconfiguration. However, UEs come in a wide variety of configurations,and FIG. 3A does not limit the scope of this disclosure to anyparticular implementation of a UE.

The UE 116 includes an antenna 305, a radio frequency (RF) transceiver310, transmit (TX) processing circuitry 315, a microphone 320, andreceive (RX) processing circuitry 325. The UE 116 also includes aspeaker 330, a main processor 340, an input/output (I/O) interface (IF)345, a keypad 350, a display 355, and a memory 360. The memory 360includes a basic operating system (OS) program 361 and one or moreapplications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RFsignal transmitted by an eNB of the network 100. The RF transceiver 310down-converts the incoming RF signal to generate an intermediatefrequency (IF) or baseband signal. The IF or baseband signal is sent tothe RX processing circuitry 325, which generates a processed basebandsignal by filtering, decoding, and/or digitizing the baseband or IFsignal. The RX processing circuitry 325 transmits the processed basebandsignal to the speaker 330 (such as for voice data) or to the mainprocessor 340 for further processing (such as for web browsing data).

The TX processing circuitry 315 receives analog or digital voice datafrom the microphone 320 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the main processor340. The TX processing circuitry 315 encodes, multiplexes, and/ordigitizes the outgoing baseband data to generate a processed baseband orIF signal. The RF transceiver 310 receives the outgoing processedbaseband or IF signal from the TX processing circuitry 315 andup-converts the baseband or IF signal to an RF signal that istransmitted via the antenna 305.

The main processor 340 can include one or more processors or otherprocessing devices and execute the basic OS program 361 stored in thememory 360 in order to control the overall operation of the UE 116. Forexample, the main processor 340 could control the reception of forwardchannel signals and the transmission of reverse channel signals by theRF transceiver 310, the RX processing circuitry 325, and the TXprocessing circuitry 315 in accordance with well-known principles. Insome embodiments, the main processor 340 includes at least onemicroprocessor or microcontroller.

The main processor 340 is also capable of executing other processes andprograms resident in the memory 360, such as operations for channelquality measurement and reporting for systems having 2D antenna arraysas described in embodiments of the present disclosure as described inembodiments of the present disclosure. The main processor 340 can movedata into or out of the memory 360 as required by an executing process.In some embodiments, the main processor 340 is configured to execute theapplications 362 based on the OS program 361 or in response to signalsreceived from eNBs or an operator. The main processor 340 is alsocoupled to the I/O interface 345, which provides the UE 116 with theability to connect to other devices such as laptop computers andhandheld computers. The I/O interface 345 is the communication pathbetween these accessories and the main controller 340.

The main processor 340 is also coupled to the keypad 350 and the displayunit 355. The operator of the UE 116 can use the keypad 350 to enterdata into the UE 116. The display 355 may be a liquid crystal display orother display capable of rendering text and/or at least limitedgraphics, such as from web sites.

The memory 360 is coupled to the main processor 340. Part of the memory360 could include a random access memory (RAM), and another part of thememory 360 could include a Flash memory or other read-only memory (ROM).

Although FIG. 3A illustrates one example of UE 116, various changes maybe made to FIG. 3A. For example, various components in FIG. 3A could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, themain processor 340 could be divided into multiple processors, such asone or more central processing units (CPUs) and one or more graphicsprocessing units (GPUs). Also, while FIG. 3A illustrates the UE 116configured as a mobile telephone or smartphone, UEs could be configuredto operate as other types of mobile or stationary devices.

FIG. 3B illustrates an example eNB 102 according to this disclosure. Theembodiment of the eNB 102 shown in FIG. 3B is for illustration only, andother eNBs of FIG. 1 could have the same or similar configuration.However, eNBs come in a wide variety of configurations, and FIG. 3B doesnot limit the scope of this disclosure to any particular implementationof an eNB. It is noted that eNB 101 and eNB 103 can include the same orsimilar structure as eNB 102.

As shown in FIG. 3B, the eNB 102 includes multiple antennas 370 a-370 n,multiple RF transceivers 372 a-372 n, transmit (TX) processing circuitry374, and receive (RX) processing circuitry 376. In certain embodiments,one or more of the multiple antennas 370 a-370 n include 2D antennaarrays. The eNB 102 also includes a controller/processor 378, a memory380, and a backhaul or network interface 382.

The RF transceivers 372 a-372 n receive, from the antennas 370 a-370 n,incoming RF signals, such as signals transmitted by UEs or other eNBs.The RF transceivers 372 a-372 n down-convert the incoming RF signals togenerate IF or baseband signals. The IF or baseband signals are sent tothe RX processing circuitry 376, which generates processed basebandsignals by filtering, decoding, and/or digitizing the baseband or IFsignals. The RX processing circuitry 376 transmits the processedbaseband signals to the controller/processor 378 for further processing.

The TX processing circuitry 374 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 378. The TX processing circuitry 374 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 372 a-372 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 374 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 370 a-370 n.

The controller/processor 378 can include one or more processors or otherprocessing devices that control the overall operation of the eNB 102.For example, the controller/processor 378 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 372 a-372 n, the RX processing circuitry 376, andthe TX processing circuitry 374 in accordance with well-knownprinciples. The controller/processor 378 could support additionalfunctions as well, such as more advanced wireless communicationfunctions. For instance, the controller/processor 378 can perform theblind interference sensing (BIS) process, such as performed by a BISalgorithm, and decodes the received signal subtracted by the interferingsignals. Any of a wide variety of other functions could be supported inthe eNB 102 by the controller/processor 378. In some embodiments, thecontroller/processor 378 includes at least one microprocessor ormicrocontroller.

The controller/processor 378 is also capable of executing programs andother processes resident in the memory 380, such as a basic OS. Thecontroller/processor 378 is also capable of supporting scheduling uplinktransmissions and random access in unlicensed carriers as described inembodiments of the present disclosure. In some embodiments, thecontroller/processor 378 supports communications between entities, suchas web RTC. The controller/processor 378 can move data into or out ofthe memory 380 as required by an executing process.

The controller/processor 378 is also coupled to the backhaul or networkinterface 382. The backhaul or network interface 382 allows the eNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 382 could support communications overany suitable wired or wireless connection(s). For example, when the eNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 382 could allow the eNB102 to communicate with other eNBs over a wired or wireless backhaulconnection. When the eNB 102 is implemented as an access point, theinterface 382 could allow the eNB 102 to communicate over a wired orwireless local area network or over a wired or wireless connection to alarger network (such as the Internet). The interface 382 includes anysuitable structure supporting communications over a wired or wirelessconnection, such as an Ethernet or RF transceiver.

The memory 380 is coupled to the controller/processor 378. Part of thememory 380 could include a RAM, and another part of the memory 380 couldinclude a Flash memory or other ROM. In certain embodiments, a pluralityof instructions, such as a BIS algorithm is stored in memory. Theplurality of instructions are configured to cause thecontroller/processor 378 to perform the BIS process and to decode areceived signal after subtracting out at least one interfering signaldetermined by the BIS algorithm.

As described in more detail below, the transmit and receive paths of theeNB 102 (implemented using the RF transceivers 372 a-372 n, TXprocessing circuitry 374, and/or RX processing circuitry 376) supportcommunication with aggregation of Frequency Division Duplexing (FDD)cells and Time Division Duplexing (TDD) cells.

Although FIG. 3B illustrates one example of an eNB 102, various changesmay be made to FIG. 3B. For example, the eNB 102 could include anynumber of each component shown in FIG. 3. As a particular example, anaccess point could include a number of interfaces 382, and thecontroller/processor 378 could support routing functions to route databetween different network addresses. As another particular example,while shown as including a single instance of TX processing circuitry374 and a single instance of RX processing circuitry 376, the eNB 102could include multiple instances of each (such as one per RFtransceiver).

A communication system includes a downlink (DL) that conveys signalsfrom transmission points such as base stations or eNBs to UEs and anuplink (UL) that conveys signals from UEs to reception points such aseNBs. A UE, also commonly referred to as a terminal or a mobile station,may be fixed or mobile and may be a cellular phone, a personal computerdevice, or an automated device. An eNB, which is generally a fixedstation, may also be referred to as an access point or other equivalentterminology.

Downlink (DL) transmissions from an eNB to a UE or uplink (UL)transmissions from the UE to the eNB can be in one or more licensedfrequency bands, in one or more unlicensed frequency bands, or both inone or more unlicensed frequency bands and one or more licensedfrequency bands. In an unlicensed frequency band, an eNB and a UEtypically content for access as the unlicensed frequency band needs tobe shared with other radio access technologies, such as Wi-Fi basedones, or with other operators deploying communications with respectiveeNB and UEs in the unlicensed band. Conversely, in a licensed frequencyband, it is not necessary for an eNB and a UE to content for access andwhen contention happens, the associated mechanism can be controlled bythe operator.

In some wireless networks, DL signals include data signals conveyinginformation content, control signals conveying DL control information(DCI), and reference signals (RS) that are also known as pilot signals.An eNB transmits data information or DCI through respective physical DLshared channels (PDSCHs) or physical DL control channels (PDCCHs). ThePDCCH can be an enhanced PDCCH (EPDDCH) but the term PDCCH will be usedfor brevity to denote PDCCH or EPDCCH. A PDCCH is transmitted over oneor more control channel elements (CCEs). An eNB transmits one or more ofmultiple types of RS including a UE-common RS (CRS), a channel stateinformation RS (CSI-RS), and a demodulation RS (DMRS). A CRS istransmitted over a DL system bandwidth (BW) and can be used by UEs todemodulate data or control signals or to perform measurements. To reduceCRS overhead, an eNB can transmit a CSI-RS with a smaller density in thetime and/or frequency domain than a CRS. For channel measurement,non-zero power CSI-RS (NZP CSI-RS) resources can be used. Forinterference measurement reports (IMRs), CSI interference measurement(CSI-IM) resources associated with zero power CSI-RS (ZP CSI-RS)resources can be used [3]. A CSI process includes NZP CSI-RS and CSI-IMresources. DMRS is transmitted only in the BW of a respective PDSCH anda UE can use the DMRS to demodulate information in a PDSCH.

In some implementations, UL signals also include data signals conveyinginformation content, control signals conveying UL control information(UCI), and RS. A UE transmits data information or UCI through arespective physical UL shared channel (PUSCH) or a physical UL controlchannel (PUCCH). When a UE simultaneously transmits data information andUCI, the UE can multiplex both in a PUSCH or the UE can transmit dataand some UCI in a PUSCH and transmit remaining UCI in a PUCCH when theeNB configures the UE for simultaneous PUSCH and PUCCH transmission. UCIincludes hybrid automatic repeat request acknowledgement (HARQ-ACK)information, indicating correct or incorrect detection of data transportblocks (TBs) in a PDSCH, scheduling request (SR) indicating whether a UEhas data in its buffer, and CSI enabling an eNB to select appropriateparameters for link adaptation of PDSCH or PDCCH transmissions to a UE.

CSI includes a channel quality indicator (CQI) informing an eNB of a DLsignal to interference and noise ratio (SINR) experienced by the UE, aprecoding matrix indicator (PMI) informing an eNB how to applybeam-forming for DL transmissions to the UE, and a rank indicator (RI)informing the eNB of a rank for a PDSCH transmission. UL RS includesDMRS and sounding RS (SRS). A UE transmits DMRS only in a BW of arespective PUSCH or PUCCH and an eNB can use a DMRS to demodulateinformation in a PUSCH or PUCCH. A UE transmits SRS to provide an eNBwith an UL CSI. A SRS transmission from a UE can be periodic (P-SRS, ortrigger type 0 SRS) or aperiodic (A-SRS, or trigger type 1 SRS) astriggered by a SRS request field included in a DCI format conveyed by aPDCCH scheduling PUSCH or PDSCH.

A transmission time interval (TTI) for DL transmission or for ULtransmission is referred to as a subframe (SF) and includes two slots. Aunit of ten SFs is referred to as a system frame. A system frame isidentified by a system frame number (SFN) ranging from 0 to 1023 and canbe represented by 10 binary elements (or bits). A BW unit for a DLtransmission or for an UL transmission is referred to as a resourceblock (RB), one RB over one slot is referred to as a physical RB (PRB),and one RB over one SF is referred to as a PRB pair. An RB includes ofN_(sc) ^(RB) sub-carriers. One sub-carrier over a SF symbol is referredto as resource element (RE). For example, a SF can have duration of onemillisecond and a RB can have a bandwidth of 180 KHz and include 12 REswith inter-RE spacing of 15 KHz. A RE is identified by the pair ofindexes (k,l) where k is a frequency domain index and l in a time domainindex. An eNB informs parameters for a PDSCH transmission to a UE orparameters for a PUSCH transmission from the UE, through a DCI formatwith cyclic redundancy check (CRC) scrambled by a cell radio networktemporary identifier (C-RNTI), that is conveyed in a PDCCH the eNBtransmits to the UE and is respectively referred to as DL DCI format orUL DCI format.

In some implementations, a UE decodes a DCI format 1A for PDSCHscheduling and a DCI format 0 for PUSCH scheduling. These two DCIformats are designed to have a same size and are often jointly referredto as DCI format 0/1A. Another DCI format, DCI format 1C, can schedule aPDSCH providing SIBs, or a random access response (RAR), or paginginformation. DCI format 1C can also be used on indicate a subframeconfiguration for operation on unlicensed spectrum (see also REF 3).Another DCI format, DCI format 3 or DCI format 3A (often jointlyreferred to as DCI format 3/3A) can provide transmission power control(TPC) commands to one or more UEs for adjusting a transmission power ofrespective PUSCHs or PUCCHs.

A DCI format includes cyclic redundancy check (CRC) bits in order for aUE to confirm a correct detection of the DCI format. A DCI format typeis identified by a radio network temporary identifier (RNTI) thatscrambles the CRC bits. For a DCI format scheduling a PDSCH or a PUSCHto a single UE, the RNTI can be a cell RNTI (C-RNTI) and serves as a UEidentifier. For a DCI format scheduling a PDSCH conveying SI, the RNTIcan be an SI-RNTI. For a DCI format scheduling a PDSCH providing a RAR,the RNTI can be an RA-RNTI. For a DCI format scheduling a PDSCH paging agroup of UEs, the RNTI can be a P-RNTI. For a DCI format indicating asubframe configuration for operation on unlicensed spectrum, the RNTIcan be a CC-RNTI. For a DCI format providing TPC commands to a group ofUEs, the RNTI can be a TPC-RNTI. Each RNTI type can be configured to aUE through higher-layer signaling such as RRC signaling. A DCI formatscheduling PDSCH transmission to a UE is also referred to as DL DCIformat or DL assignment while a DCI format scheduling PUSCH transmissionfrom a UE is also referred to as UL DCI format or UL grant.

A PDCCH conveying a DCI format scheduling a PDSCH to a UE or a PUSCHfrom a UE can be transmitted in a same DL cell as the PDSCH transmissionor in a same DL cell as the DL cell linked to an UL cell for the PUSCHtransmission. This is referred to as self-scheduling. In case a UE isconfigured for operation with carrier aggregation (CA), the PDCCHtransmitted in a different DL cell than a DL cell of an associated PDSCHor a DL cell linked to an UL cell of an associated PUSCH.

Table 1 provides information elements (IEs), or fields, for a DCI formatscheduling a PUSCH transmission with a maximum of one data TB within aBW of N_(RB) ^(UL).

TABLE 1 IEs of a DCI Format Scheduling PUSCH (based on a DCI Format 0)DCI Format 0 IE Number of Bits Functionality Differentiation Flag 1Differentiates DCI Format 0 from DCI Format 0 vs. DCI Format 1A DCIFormat 1A Cross-carrier indicator field (CIF) 0 or 3 Enabled only whenUE is configured with CA and cross-carrier scheduling RB assignment andhopping ┌log₂(N_(RB) ^(UL)(N_(RB) ^(UL) + 1)/2)┐ Assigns PUSCH RBsresource allocation Frequency hopping (FH) Flag 1 Indicates whether ornot PUSCH is with FH Modulation and Coding Scheme 5 Provides MCS fordata TB (MCS) HARQ process number 4 Provides a HARQ process number (seealso REF 2) Redundancy Version (RV) 2 Provide a RV for data TB encoding(see also REF 2) NDI 1 Indicates new transmission or re-transmission ofdata TB TPC Command 2 Adjusts PUSCH transmission power CS and OCC Index3 CS and OCC for PUSCH DMRS CSI Request 1 Indicates whether UE shallinclude CSI reports in PUSCH SRS Request 1 Indicates whether UE shalltransmit SRS DF Assignment Index (DAI) 2 Number of DL assignments fortransmission of associated HARQ-ACK in PUSCH (see also REF 3) UL Index 2Number of SFs for PUSCH transmissions (see also REF 3) Padding Bits (forsize 0 = size 1A) Variable For same size of DCI Format 0 and DCI Format1A C-RNTI 16  Identifies UE for DCI Format 0

FIG. 4 illustrates an example encoding process for a DCI format for usewith an eNB according to this disclosure. The embodiment of encodingprocess for a DCI format shown in FIG. 4 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

An eNB separately codes and transmits each DCI format in a respectivePDCCH. A RNTI for a UE, for which a DCI format is intended, masks a CRCof a DCI format codeword in order to enable the UE to identify that aparticular DCI format is intended for the UE. The CRC of (non-coded) DCIformat bits 410 is determined using a CRC computation operation 420, andthe CRC is masked using an exclusive OR (XOR) operation 430 between CRCbits and RNTI bits 440. The XOR operation 430 is defined as XOR(0,0)=0,XOR(0,1)=1, XOR(1,0)=1, XOR(1,1)=0. The masked CRC bits are appended toDCI format information bits using a CRC append operation 150. Channelcoding is performed using a channel coding operation 460 (such as tailbiting convolutional coding (TBCC)), followed by a rate matchingoperation 470 applied to allocated resources. Interleaving andmodulation operations 480 are performed, and the output control signal490 is transmitted. In the present example, both a CRC and an RNTIinclude 16 bits; however, it will be understood that either or both ofthe CRC and the RNTI could include more or fewer than 16 bits.

FIG. 5 illustrates an example decoding process for a DCI format for usewith a UE according to this disclosure. The embodiment of decodingprocess for a DCI format in FIG. 5 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

A UE performs reverse operations of an eNB transmitter to determinewhether the UE has a DCI format assignment in a DL SF. A receivedcontrol signal 510 is demodulated and the resulting bits arede-interleaved at operation 520. A rate matching applied at an eNBtransmitter is restored through operation 530, and data is decoded atoperation 540. After decoding the data, DCI format information bits 560are obtained after extracting CRC bits 550. The DCI format informationbits are de-masked 570 by applying the XOR operation with a RNTI 580. AUE performs a CRC check 590. If the CRC check passes, the UE determinesthat the DCI format corresponding to the received control signal 510 isvalid and determines parameters for signal reception or signaltransmission. If the CRC test does not pass, the UE disregards thepresumed DCI format.

FIG. 6 illustrates an example UL SF structure for PUSCH transmission orPUCCH transmission according to this disclosure. The embodiment shown inFIG. 6 is for illustration only. Other embodiments could be used withoutdeparting from the scope of the present disclosure.

UL signaling can use Discrete Fourier Transform Spread OFDM(DFT-S-OFDM). A SF 610 includes two slots and each slot 620 includesN_(symb) ^(UL) symbols 630 where UE transmits data information, UCI, orRS including one symbol per slot where the UE transmits DMRS 640. Asystem BW includes N_(RB) ^(UL) RBs. Each RB includes N_(sc) ^(RB)(virtual) REs. A UE is assigned M_(PUXCH) RBs 640 for a total of M_(sc)^(PUXCH)=M_(PUXCH)·N_(sc) ^(RB) REs 650 for a PUSCH transmission BW(‘X’=‘S’) or for a PUCCH transmission BW (‘X’=‘C’). A last SF symbol canbe used to multiplex SRS transmissions 660 from one or more UEs. Anumber of UL SF symbols available for data/UCI/DMRS transmission isN_(symb) ^(PUXCH)=2·(N_(symb) ^(UL)−1)−N_(SRS)·N_(SRS)=1 when a last SFsymbol supports SRS transmissions from UEs that overlap at leastpartially in BW with a PUXCH transmission BW; otherwise, N_(SRS)=0.Therefore, a number of total REs for a PUXCH transmission is M_(sc)^(PUXCH)·N_(symb) ^(PUXCH).

FIG. 7 illustrates a transmitter block diagram for UCI and data in aPUSCH according to this disclosure. The embodiment shown in FIG. 7 isfor illustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

Coded and modulated CSI symbols 705, when any, and coded and modulateddata symbols 710, when any, are multiplexed by multiplexer 720. HARQ-ACKsymbols, when any, are also multiplexed, data/CSI is punctured bypuncturing unit 730 to accommodate HARQ-ACK in overlapping REs.Subsequently, a discrete Fourier transform (DFT) filter 740 applies aDFT, a transmission BW selector 755 selects REs 750 corresponding to anassigned transmission BW, filter applies an inverse fast Fouriertransform (IFFT) 760, followed by time-domain filtering by filter 770and a signal transmitted 780. Encoders, modulators, cyclic prefixinsertion, as well as other processing units such as a power amplifieror RF filtering are well known in the art and are omitted for brevity.

FIG. 8 illustrates a receiver block diagram for UCI and data in a PUSCHaccording to this disclosure. The embodiment shown in FIG. 8 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

A digital signal 810 is filtered 820, a filter applies a fast Fouriertransform (FFT) 830, a reception BW selector 845 selects REs 840 used bya transmitter, filter 850 applies an inverse DFT (IDFT), HARQ-ACKsymbols are extracted and respective erasures for data/CSI symbols areplaced by unit 860, and a de-multiplexer 870 de-multiplexes data symbols880 and CSI symbols 585. Demodulators, decoders, cyclic prefixextraction, as well as other processing units such as analog-to-digitalconverted or radio frequency (RF) filtering are well known in the artand are omitted for brevity.

The transmitter structure in FIG. 7 and the receiver structure in FIG. 8can also be used for a PUCCH transmission using a PUCCH Format 4 or aPUCCH Format 5. An exception is that HARQ-ACK and CSI are jointly,instead of separately, encoded (and there is no data transmission).

An RB allocation for a PUSCH transmission, also referred to as resourceallocation (RA), can be either over a single interlace of contiguous RBs(RA type 0) or over two non-contiguous interlaces of contiguous RBs (RAtype 1). An UL grant includes a RA field indicating a RA for anassociated PUSCH transmission.

For RA type 0, a RA field indicates to a UE a set of contiguouslyallocated (virtual) RB indices denoted by n_(VRB). The RA field includesa resource indication value (RIV) corresponding to a starting RB(RB_(START)) and a length in terms of contiguously allocated RBs(L_(CRBs)≥1). The RIV is defined by RIV=N_(RB)^(UL)·(L_(CRBs)−1)+RB_(START) when (L_(CRBs)−1)≤└N_(RB) ^(UL)/2┘, and byRIV=N_(RB) ^(UL)·(N_(RB) ^(UL)+L_(CRBs)−1)+(N_(RB) ^(UL)−1−RB_(START))when (L_(CRBs)−1)>└N_(RB) ^(UL)/2┘.

For RA type 1, a RA field indicates to a UE two sets of RBs with eachset including one or more consecutive RB groups (RBGs) of size P. Acombinatorial index r includes

$\left\lceil {\log_{2}\begin{pmatrix}\left\lceil {{N_{RB}^{UL}\text{/}P} + 1} \right\rceil \\4\end{pmatrix}} \right\rceil$bits where ┌ ┐ is the ceiling function that rounds a number to itsimmediately next larger integer. The bits from the RA field typicallyrepresent r (see also REF 3). The combinatorial index r corresponds to astarting and ending RBG index of RB set 1, s₀ and s₁−1, and RB set 2, s₂and s₃−1 respectively, and

$r = {\sum\limits_{i = 0}^{M - 1}\;\left\langle \begin{matrix}{N - s_{i}} \\{M - 1}\end{matrix} \right\rangle}$with M=4 and N=|N_(RB) ^(UL)/P+1|.

When using an unlicensed frequency band for communication between an eNBand a UE, such communication can often have to satisfy regulatoryrequirements for using the unlicensed frequency band. A firstrequirement can be that a transmission from either the eNB or the UEoccupies at least eighty percent (80%) of an available BW on theunlicensed frequency band. A second requirement can be that atransmission power per megahertz (MHz), also referred to as powerspectral density (PSD), does not exceed a predefined value such as 10 or13 decibels (dB) per milliwatt (dBm). A maximum PSD requirement canresult to a limited coverage for transmission from a UE to an eNB whenusing an unlicensed frequency band. Typically, a maximum UE transmissionpower can be 23 dBm but a UE needs to reduce it, for example to 10 dBm,when the UE transmits a signal with continuous BW occupation over 1megaHertz (MHz). One way to satisfy a maximum PSD requirement whileavoiding materially compromising UL coverage is for a UE to transmit asignal having a discontinuous BW occupation. For example, a UE cantransmit an UL channel, such as a PUSCH or a PUCCH, over one or more RBsthat are interleaved throughout a BW of an unlicensed frequency band sothat the PSD in the one or more RBs, each RB spanning 180 KHz, can be 17dBm but the PSD can be less than 10 dBm/MHz.

Additional requirements can also exist. For example, a third requirementcan be that prior to transmitting on an unlicensed cell, an eNB or a UEneed to perform carrier sensing and apply a listen before talk (LBT)procedure to contend for access to the unlicensed frequency band. An LBTprocedure can include a clear channel assessment (CCA) procedure todetermine whether or not a channel in the unlicensed frequency band isavailable. When the CCA determines that the channel is not available,for example because it is used by another device such as a WiFi device,the eNB or the UE can apply an extended CCA procedure to increase alikelihood of gaining access to the unlicensed frequency band. Anextended CCA procedure includes a random number of CCA procedures (from1 to q) according to an extended CCA counter. Each CCA procedure caninclude detecting an energy level on the channel of the unlicensedfrequency band and determining whether or not the energy level is belowa threshold. When the energy level is at or below the threshold, the CCAprocedure is successful and the eNB or the UE can access the channel.When the energy level is above the threshold, the CCA procedure isunsuccessful and the eNB or the UE cannot access the channel.

Scheduling Uplink Transmissions in Unlicensed Bands

FIG. 9 illustrates a transmission of an UL channel transmission, such asa PUSCH or a PUCCH, over ten RBs interleaved in frequency according tothis disclosure. The embodiment shown in FIG. 9 is for illustrationonly. Other embodiments could be used without departing from the scopeof the present disclosure.

An UL channel transmission is in groups of interleaved RBs where a groupof interleaved RBs is referred to as interlace. Each interlace includesRBs separated by 10 RBs in a system BW. For a 20 MHz BW that includes100 RBs, there are 10 interlaces of RBs and each interlace includes 10RBs. A first UE is allocated a first interlace of RBs 910 and a secondUE is allocated a second interlace of RBs 920. A UE can be allocatedmultiple interlaces up to all interlaces of RBs in a system BW. Otherrealizations are also possible such as for example a number of 5interlaces with 20 equally spaced RBs per interlace. For a PUSCHtransmission or for a PUCCH transmission from a UE on an unlicensedcell, transmission in one or more of last SF symbols or one or morefirst SF symbols can be suspended in order for the UE or for other UEsto perform CCA and the SF structure in FIG. 9 can be modifiedaccordingly.

Since an interlace includes non-contiguous RBs, a channel estimate for aPUSCH transmission over an interlace needs to generally be obtained perRB due to a possible frequency selective channel. This results to adegraded accuracy for a channel estimate as only REs in one PRB can beused and creates edge effects for first and last REs in a RB. It isdesirable for a PUSCH transmission over multiple interlaces to enableenhancing an accuracy of a respective channel estimate.

Moreover, a UE typically needs to perform a CCA before transmitting aPUSCH in SF n response to a detection of a DCI format in SF n−k, wheretypically k≥4, it is possible that the CCA fails and the UE does nottransmit the PUSCH. In heavily loaded cells where many UEs can contendfor access to a channel medium at a time, it is likely that the PDCCHtransmissions conveying UL grants to UEs are not reciprocated byrespective PUSCH transmission. To reduce a possible waste in DLresources for PDCCH transmissions scheduling PUSCH transmissions that donot materialize, multi-SF scheduling is one solution where an UL grantschedules multiple PUSCH transmissions over respective multiple SFs byincluding a multi-SF allocation field indicating a number of PUSCHtransmissions. With multi-SF scheduling, a single resource allocationvalue, a single MCS value, and a single CS/OCC value are applicable forall of the multiple PUSCH transmissions. Unavailability of an unlicensedcell for PUSCH transmissions at a SF also requires that PUSCHretransmissions are supported by an asynchronous HARQ process.Therefore, multi-SF PUSCH scheduling needs to accommodate PUSCHtransmissions for different HARQ processes. Additionally, A-CSImultiplexing over multiple PUSCH transmissions needs to be supported as,with multi-SF scheduling, there is only a single opportunity to triggerA-CSI reporting over multiple SFs.

Therefore, there is a need to define allocation of multiple interlacesfor a PUSCH transmission in order to improve channel estimation accuracyand design a respective resource allocation field in an UL grant.

There is another need to enable multi-SF PUSCH scheduling of multiplePUSCH transmissions for asynchronous HARQ retransmissions withoutsignificantly increasing an UL grant size.

Also, there is another need to enable A-CSI multiplexing over multiplePUSCH transmissions in order to accommodate a single A-CSI triggeringopportunity over multiple SFs in case of multi-SF scheduling.

In the following, unless otherwise explicitly mentioned, reference iswith respect to PUSCH transmissions over one or more interlaces.

Resource Allocation for PUSCH Transmission Over Interlaces

A UE can be allocated by an eNB one or more interlaces of RBs for aPUSCH transmission. When the UE is allocated multiple interlaces, it ispreferable that the interlaces result to contiguous RBs in order toimprove channel estimation by utilizing single filters over thecontiguous RBs instead of obtaining a channel estimate per RB that wouldbe necessary in case of non-contiguous RBs due to a frequency selectivechannel. PUSCH transmission over contiguous RBs when an eNB allocates toa UE a number of interlaces for PUSCH transmission is realized byassigning interlaces with consecutive indexes. Therefore, even thoughthe RBs of each interlace are non-contiguous and are substantiallydistributed over the system BW, blocks of contiguous RBs can result byassigning interlaces with consecutive indexes for a PUSCH transmission.

FIG. 10 illustrates an example of an allocation of two interlaces withconsecutive indexes for a PUSCH transmission from a first UE and anexample of an allocation of two interlaces with non-consecutive indexesfor a PUSCH transmission from a second UE according to this disclosure.The embodiment shown in FIG. 10 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

There are 10 interlaces in a system BW and are indexed from 0 to 9according to an ascending order of a lowest indexed RB in eachinterlace. A first UE is allocated two interlaces with contiguousindexes of 5 and 6, 1010 and 1012, for a PUSCH transmission to an eNB. Asecond UE is allocated two interlaces with non-contiguous indexes of 2and 8, 1020, 1022, 1024, and 1026, for a PUSCH transmission to an eNB.Due to the separation of the RBs for interlaces with indexes 2 and 8 anda possible frequency selective channel medium, the eNB cannot apply asingle channel estimator over the two RBs. As a consequence, channelestimation accuracy for a PUSCH reception for the second UE is degradedand a resulting reception reliability of a respective data TB is alsodegraded.

In order to realize performance and implementation complexity benefits,this disclosure provides that interlaces of RBs allocated to a PUSCHtransmission have consecutive indexes. Allocation of a number ofinterlaces for a PUSCH transmission is referred to as RA type 3. For aPUSCH transmission over M_(I) interlaces, from a total of N_(I) ^(UL)interlaces of an UL system BW, and subject to a restriction that theindexes of the M_(I) interlaces are consecutive, a RA field in anassociated UL grant includes ┌log₂(M_(I)·(M_(I)+1)/2)┐ bits providing aresource indication value for interlaces RIV_(I). Similar to RA type 0,RIV_(i) indicates a starting interlace (I_(START)) and a length in termsof contiguously allocated RBs (L_(CIs)≥1) and is defined byRIV_(I)=N_(I) ^(UL)·(L_(CIs)−1)+I_(START) when (L_(CIs)−1)≤└N_(I)^(UL)/2┘, and by RIV_(I)=N_(I) ^(UL)·(N_(I) ^(UL)+L_(CIs)−1)+(N_(I)^(UL)−1−I_(START)) when (L_(CIs)−1)>└N_(I) ^(UL)/2┘. For example, for a20 MHz system BW that includes 100 RBs, there are N_(I) ^(UL)=10interlaces in case of 10 RBs per interlace and a number of required bitsfor the RA type 3 field in an UL grant is 6 while there are N_(I)^(UL)=20 interlaces in case of 5 RBs per interlace and a number ofrequired bits for the RA type 3 field in an UL grant is 8. As forM_(I)=10 interlaces or for M_(I)=20 interlaces it isM_(I)·(M_(I)+1)/2<2^(┌log) ² ^((M) ^(I) ^(·(M) ^(I) ^(+1)/2┐), remainingstates (for M_(I)·(M_(I)+1)/2≤RIV_(I)≤2^(┌log) ² ^((M) ^(I) ^(·(M) ^(I)^(+1)/2┐)−1) can be used to indicate other combinations of clusters withnon-contiguous indexes, such as clusters 0 and 5, as is subsequentlydiscussed for transmission of a Msg3 associated with a random accessprocess.

Multi-SF Scheduling of PUSCH Transmissions

In a first example multi-SF scheduling is enabled by including amulti-SF allocation field in an UL grant. For example, for a maximumnumber of N_(SF)=4 SFs for multi-SF PUSCH transmissions, a multi-SFallocation field of ┌log₂(N_(SF))┐=2 bits in an UL grant can indicatescheduling of one or more PUSCH transmissions over 1 SF, 2 SFs, 3 SFs,or 4 SFs. A limitation for the multi-SF scheduling in the first exampleis that an SF for a first PUSCH transmission needs to be predetermined,for example by a timing relation relative to a SF of a PDCCHtransmission conveying an associated UL grant.

In a second example, an index field for a first SF of a PUSCHtransmission can also be included in an UL grant.

In a first approach, an index field is a separate field than a multi-SFallocation field. For example, a maximum number of N_(SF)=4 SFs formulti-SF PUSCH transmissions, an index field of 2 bits can indicate afirst SF can for a respective PUSCH transmission. This can enable an eNBto opportunistically transmit PDCCH to a UE in a first SF, depending onavailable PDCCH capacity in the first SF or depending, for example, onan availability of an unlicensed cell in the first SF, in order toschedule a PUSCH transmission from the UE in a second SF without thesecond SF being constrained to be a first UL SF where the UE cantransmit PUSCH that occurs at least four SFs after the first SF.Equivalently, for a PDCCH transmission in SF n, an index field in a DCIformat with value o_(t) can act as a timing offset to a PUSCHtransmission SF that can be determined as an UL SF with index n+k+o_(t)(modulo 10) where n+k is an earliest UL SF where PUSCH can betransmitted and, for example, k≥4.

In a second approach, similar to UL/DL configuration 0 in a TDD system,an UL index field of 4 bits in an UL grant that functions as a bit-mapcan indicate both a number of SFs for a same number of PUSCHtransmissions and a first SF for the number of PUSCH transmissions. Forexample, a bit-map of 4 bits with values {0, 1, 1, 1} can indicate thatan associated UL grant schedules PUSCH transmissions over a second, athird, and a fourth SF and that the SF for a first PUSCH transmission isthe second SF. A disadvantage of the second approach occurs when N_(F)is large as a bit-map size is equal to the value of N_(SF).

When a UE detects an UL grant that schedules PUSCH transmissions on acell over a number of two or more SFs and over a number of M_(I)interlaces, it can be beneficial to randomize an interference caused bythe multiple PUSCH transmissions to transmissions in neighboring cellsusing a same frequency band. For a PUSCH transmission with RA type 3(interlace), frequency domain scheduling is not material and the M_(I)interlaces can be any of the N_(I) ^(UL) interlaces of an UL system BW(potentially subject to the M_(I) interlaces having contiguous indexes).A shift can then apply on the indexes of interlaces used for each PUSCHtransmissions in different SFs by adding the cell-specific shift to alowest interlace index from the indexes (modulo N_(I) ^(UL)).

In a first example, the shift can be time-invariant and cell-specificsuch as (PCID)mod N_(I) ^(UL) where PCID is a physical cell ID for thecell. For example, for N_(I) ^(UL)=10 and (PCID)mod N_(I) ^(UL)=2, whenfour interlaces with indexes 2, 3, 4, 5 are assigned by an UL grant fora PUSCH transmission over four SFs, the first, second, third, and fourthPUSCH transmissions can be on interlaces with indexes {2, 3, 4, 5}, {4,5, 6, 7}, {6, 7, 8, 9}, and {8, 9, 0, 1}, respectively. Some indexes ofinterlaces, such as for example index 0, can precluded from use as theycan be semi-statically configured for other transmissions such as PUCCHor PRACH transmissions. For example, for N_(I) ^(UL)=10 and wheninterlace with index 0 is precluded, a cycling of interlaces for themultiple PUSCH transmissions can be over the indexes of interlaces from1 to 9.

FIG. 11 illustrates an example of shifting for interlace indexes usedfor multiple PUSCH transmissions from a UE according to this disclosure.The embodiment shown in FIG. 11 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

A UE detects an UL grant transmitted from an eNB that schedules twoPUSCH transmissions over two respective SFs on a cell having a PCID anda system BW that includes N_(I) ^(UL)=10 interlaces of RBs. The UEdetermines an offset value (PCID)mod N_(I) ^(UL)=2. An RA type 3 fieldin the UL grant indicates a first transmission on interlaces 3, 4, and5, 810 and 1112, and the UE transmits the PUSCH in the first SF oninterlaces 3, 4, and 5, 1110 and 1112. The UE transmits the PUSCH in thesecond SF on interlaces 5, 6, and 7, 1120 and 1122.

In a second example, the shift can be time-variant such as└(n_(s)−n_(s0))/2┘mod N_(I) ^(UL) where n_(s) is an index of a slot in aframe ranging from 0 to 19 and n_(s0) is an index of a slot for a firstPUSCH transmission from the multi-SF PUSCH transmissions triggered by anUL grant. Operation is similar to a cell-specific shift.

In a third example, the shift can be both time-variant and cell-specificby combining the approaches in the first example and the second example.

When PUSCH retransmissions are asynchronous, an UL grant needs toinclude a field for a HARQ process number, a field for a RV, and a fieldfor a NDI as for example in Table 1. For multi-SF PUSCH scheduling, thisimplies that a HARQ process number field, a RV field, and an NDI fieldneed to be include in the UL grant for each PUSCH transmission. Allother fields in the UL grant scheduling multiple PUSCH transmissions toa UE are applicable for each of the multiple PUSCH transmissions. Forexample, same respective values for an interlace assignment, a MCS, andan OCC/CS apply. A TPC command value is applied in a first PUSCH, fromthe multiple PUSCH, that the UE is able to transmit and an associatedtransmission power adjustment remains applicable for the remaining PUSCHtransmissions from the multiple PUSCH transmissions.

In order to avoid having a variable size for an UL grant depending on arespective number of PUSCH transmission that the UL grant schedules, anHARQ process number field, a RV field, and an NDI field need to beincluded in the UL grant for a maximum possible number of scheduledPUSCH transmissions. For example, for a maximum number of 4 PUSCHtransmissions that can be scheduled by an UL grant, the UL grant needsto include 4 HARQ process number fields, 4 RV fields, and 4 NDI fieldsregardless of an actual number of scheduled PDSCH transmissions that canbe smaller than 4. A typical size for a HARQ process number field is 3or 4 bits, a typical size for a RV field is 2 bits, and a NDI size is 1bit, thereby resulting to a total size of 24 to 28 bits that representsa substantial increase in a size of an UL grant scheduling a singlePUSCH transmission that is typically about 50 bits.

An increase in an UL grant size supporting scheduling of PUSCHtransmissions in respective multiple SFs can be avoided by linking avalue for each of HARQ process number, RV, and NDI for a PUSCHtransmissions in a later SF to a HARQ process number, RV, and NDI for aPUSCH transmission in a first SF from the multiple SFs. A value for eachof the HARQ process number, RV, and NDI for the PUSCH transmission inthe first SF is indicated by respective fields in the UL grant.

In a first example, the above link is predefined such as for example byapplying a same NDI value, a same RV value, and a serial increase in aHARQ process number, modulo the maximum HARQ process number, accordingto a serial increase of a number of SF, from the multiple SFs, relativeto the first SF. For example, when an UL grant schedules PUSCHtransmissions in 4 SFs and indicates a first HARQ process numbern_(HARQ) for a PUSCH transmission in the first SF, from a total ofN_(HARQ) HARQ processes, the HARQ process number for PUSCH transmissionsin the second, third, and fourth SFs are respectively (n_(HARQ)+1)modN_(HARQ), (n_(HARQ)+2)mod N_(HARQ), and (n_(HARQ)+3)mod N_(HARQ).Therefore, a HARQ process number associated with a j-th PUSCHtransmission, 1<j≤N_(SF), is (n_(HARQ)+j−1)mod N_(HARQ).

FIG. 12 illustrates an example determination of a HARQ process number incase of multi-SF PUSCH scheduling by an UL grant according to thisdisclosure. The embodiment shown in FIG. 12 is for illustration only.Other embodiments could be used without departing from the scope of thepresent disclosure.

In a first SF, SF #1 1210, an eNB transmits and a UE detects an ULgrant. The UL grant includes a HARQ process number field, a multi-SFindex field, and a first-SF index field. The multi-SF index field valueindicates scheduling of PUSCH transmissions over two SFs. The first-SFindex field value indicates a first SF that is 5 SFs after the SF of theUL grant detection. For example, the first-SF index field can include 2bits where the value of ‘00’, ‘01’, ‘10’, and ‘11’ are respectivelyinterpreted to introduce an offset of 0, 1, 2, and 3 SFs after thefourth SF (SF #5 1212) relative to the SF of the UL grant detection fora first SF of a PUSCH transmission. Then, in the present example, thefirst-SF index field has a value of ‘01’. The HARQ process number fieldhas a value of n_(HARQ) indicating a HARQ process from a total ofN_(HARQ) processes. The UE transmits a data TB for HARQ process withnumber n_(HARQ) in a first PUSCH in SF #6 1220 and transmits a data TBfor HARQ process with number (n_(HARQ)+1)mod N_(HARQ) in a second PUSCHin SF #6 1230.

The first example requires that all multiple PUSCH transmissions have asame NDI and a same RV and consecutive HARQ process numbers. Using asame RV when a different RV is preferable, or reducing a number ofsupported RVs for example from RV0, RV2, RV3, and RV1 to RV0 and RV2 fora corresponding reduction in a number of required bits from 2 to 1, onlyresults to a minor degradation in PUSCH reception reliability and it isnot a limiting factor for the first example. Using the same NDI is morerestrictive as it precludes multi-SF scheduling when a first number fromthe multiple PUSCH transmissions need to be retransmissions for data TBsfor respective HARQ processes and a remaining number from the multiplePUSCH transmissions need to be new transmissions for data TBs forrespective HARQ processes. Given the smaller communication reliabilityon an unlicensed cell, it can be a frequent event that consecutive HARQprocesses correspond to retransmissions of data TBs and newtransmissions of data TBs.

In a second example, same mechanisms as in the first example apply withthe exception that a 1-bit NDI field is included in an UL grantsupporting multi-SF scheduling for each of a respective maximum numberN_(SF) of PUSCH transmissions. This maximum number can be specified in asystem operation. For example, for an UL grant capable of scheduling amaximum number of 4 PUSCH transmissions, an additional 3 NDI bits areincluded relative to the first example, for a total of 4 NDI bits.Therefore, the second example enables substantial flexibility inmulti-SF scheduling for a marginal increase in an associated UL grantsize.

In a third example, a size of an UL grant scheduling a single PUSCHtransmission and a size of an UL grant scheduling multiple PUSCHtransmissions is same in order to adaptively support either a singlePUSCH transmission or multiple PUSCH transmissions without increasing anassociated required number of PDCCH decoding operations at a UE. A 1-bitUL flag field is introduced in an UL grant for single-SF scheduling andin an UL grant for multi-SF scheduling in order to differentiate arespective UL grant type. An RV field is not included in an UL grant formulti-SF scheduling that can be restricted to be used only for initialtransmissions of respective data TBs. An UL grant for single-SFscheduling can be used either for initial transmission or for aretransmission of data TBs. By disabling the function of the RV fieldthat exists in an UL grant for single-SF scheduling, the respective bitscan be used to have a multi-SF field function as an UL index field usinga bit-map, as it was previously described, that indicates both a numberof PUSCH transmissions and the respective SFs.

Combinations for the previous three examples are also possible. Forexample, the RV field can be excluded also for the first example and aUE can use by default a RV value of 0 when a NDI value is 1 and use a RVvalue of 2 when the NDI value is 0.

FIG. 13 illustrates an example determination by a UE of a RV to applyfor a data TB transmission depending on a value of a NDI field. Theembodiment shown in FIG. 13 is for illustration only. Other embodimentscould be used without departing from the scope of the presentdisclosure.

A UE detects an UL grant 1310. The UL grant includes a NDI field, a HARQprocess number field, and does not include a RV field. The UE examineswhether or not a value of the NDI field is 0 1320. When the value of theNDI field is 0, the UE uses a first predetermined RV value, such as a RVvalue of 2, for a retransmission of a data transport block correspondingto a HARQ process indicated by the HARQ process number field 1330. Whenthe value of the NDI field is 1, the UE uses a second predetermined RVvalue, such as a RV value of 0, for a new transmission of a data TBcorresponding to a HARQ process indicated by the HARQ process numberfield 1340.

UCI Multiplexing for Multi-SF Scheduling of PUSCH Transmissions

When a UE detects an UL grant transmitted from an eNB and schedulingmultiple PUSCH transmissions in respective multiple SFs and triggeringan A-CSI report, the UE can multiplex the A-CSI report in the first SFwhere the UE can transmit a PUSCH. However, for operation on unlicensedspectrum, the eNB (or the UE) cannot know in advance the first SF wherethe UE can transmit PUSCH, the MCS and resource allocation are same forall PUSCH transmissions, and the UE cannot always increase a PUSCHtransmission power when the UE multiplexes A-CSI in the PUSCH in orderto offset a reduction in a code rate for the date.

In another realization, A-CSI reports for individual cells, or SF sets,or processes can be distributed across the multiple PUSCH transmissionsin order to provide a somewhat uniform impact on the data informationand avoid a need for a material increase in a power of a PUSCHtransmission that includes UCI relation to a power of other PUSCHtransmissions. For example, for an UL grant scheduling N_(PUSCH)transmissions and triggering N_(CSI)>N_(PUSCH) reports, each PUSCHtransmission except for the first PUSCH transmission can include└N_(CSI)/N_(PUSCH)┘ A-CSI reports and the first PUSCH transmission caninclude ┌N_(CSI)/N_(PUSCH)┐ A-CSI reports. A-CSI reports can havedifferent sizes and therefore different A-CSI payloads can bemultiplexed in different PUSCH transmissions despite a number of A-CSIreports being same. Also, an eNB can also trigger a number of A-CSIreports that is larger than a maximum number of A-CSI reports that canbe supported in a single PUSCH transmission.

FIG. 14 illustrates an example for multiplexing a number of CSI reportsin a number of PUSCH transmission scheduled by an UL grant according tothis disclosure. The embodiment shown in FIG. 14 is for illustrationonly. Other embodiments could be used without departing from the scopeof the present disclosure.

In a first SF, SF #1 1410, an eNB transmits and a UE detects an ULgrant. The UL grant includes an A-CSI request field and a multi-SF indexfield. The A-CSI request field value maps to a state corresponding to anumber of N_(CSI) CSI reports for respective cells, or SF sets, or CSIprocesses. The UE transmits ┌N_(CSI)/2┐ CSI reports in a first PUSCHover a first SF 1420. The UE transmits └N_(CSI)/2┘ CSI reports in asecond PUSCH over a second SF 1430. When the UE is unable to transmitthe first PUSCH in the first SF, the UE can be configured to multiplexall N_(CSI) CSI reports in the second PUSCH in the second SF.

When a UE detects an UL grant transmitted from an eNB and schedulingmultiple PUSCH transmissions in respective multiple SFs and the UE needsto multiplex HARQ-ACK information in one of the multiple PUSCHtransmissions according to a timing relation between detected DLassignments and transmission of respective HARQ-ACK information, unlikethe A-CSI transmission, the UE does not postpone the HARQ-ACKtransmission to a next PUSCH transmission when the UE is not capable totransmit the PUSCH where the HARQ-ACK information needs to bemultiplexed according to the timing relation. Instead, the UE transmitsthe HARQ-ACK information either in a PUSCH or PUCCH on a licensed cellor in a PUSCH or PUCCH of another unlicensed cell where the UE. A UE canbe configured with PUCCH resources in multiple unlicensed cells toimprove a likelihood that the UE is able to transmit PUCCH at theexpense of some loss in spectral efficiency.

One fundamental requirement in an operation of a communication system isa capability for a UE to establish a connection setup with an eNB or tosynchronize its transmission with the eNB; a respective process iscommonly referred to as random access. Random access is used for severalpurposes, including: initial access when establishing a radio link;re-establishing a radio link after radio-link failure (RLF), handoverwhen UL synchronization needs to be established to a new cell, ULsynchronization, UE positioning based on UL measurements, and as a SR atleast when a UE is not configured dedicated SR resources on a PUCCH.Random access can be either contention based (multiple UEs can possiblyuse a same resource to transmit a random access preamble to an eNB) orcontention-free (an eNB assigns a dedicated resource for a random accesspreamble transmission to a UE).

FIG. 15 illustrates an overview of a contention-based random accessprocess according to this disclosure. The embodiment shown in FIG. 15 isfor illustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

In Step 1 a UE acquires information for physical random access channel(PRACH) resources 1510 from an eNB and determines resources for a randomaccess (RA) preamble transmission 1520 (also referred to as PRACHtransmission). In Step 2, the UE receives a RAR 1530 from the eNB. InStep 3, the UE transmits a PUSCH that is referred to as message 3 (Msg3)1540 to the eNB. In Step 4, the eNB and the UE perform contentionresolution 1550 through a message that is conveyed in a PDSCH and isreferred to as message 4 (Msg4). As is subsequently discussed, only thefirst two steps are needed for contention-free random access.

The four steps in FIG. 15 are now described in more detail. In Step 1,for contention-based random access, a UE acquires a SIB that conveysinformation for PRACH resources and for a PRACH format (examples arepresented in FIG. 16). PRACH resources includes a set of SFs where aPRACH transmission can occur, of RBs where a PRACH can be transmitted inthe frequency domain, and of a number of (64−N_(cf)) Zadoff-Chu (ZC)sequences for a UE to select from to generate an RA preamble (N_(cf) isa number of ZC sequences reserved by an eNB to use for contention-freePRACH transmissions). A PRACH occupies 6 RBs. A UE transmits a PRACHusing the determined PRACH resources thereby allowing an eNB to estimatetransmission timing for the UE. UL synchronization is necessary asotherwise a UE cannot properly communicate other UL signaling to an eNBand can interfere with other UEs. Contention-free random access istriggered by an eNB through a transmission of a DCI format to the UE,referred to as PDCCH order, triggering a PRACH transmission from the UE.The PDCCH conveys a DCI format 1A that includes a RA preamble index anda RA preamble mask index that enables collision avoidance for the RApreamble transmission.

In Step 2, upon detecting a RA preamble transmitted from a UE, an eNBtransmits a DCI format with CRC scrambled by a RA-RNTI and scheduling aPDSCH conveying a RAR. The RAR includes a timing advance (TA) commandfor the UE to adjust its transmission timing. The RAR also includes theassociated RA preamble in order to link the TA command to a respectiveRA preamble and therefore to a respective UE. The RAR can also includean UL grant for the UE to transmit an Msg3 and a temporary C-RNTI(TC-RNTI) in case of contention-based random access or a PUSCH conveyingdata in case of contention-free random access. When a UE fails todetect, within a RAR time window configured by the eNB, a RAR thatincludes an RA preamble transmitted by the UE, the UE retransmits aPRACH, increases a respective preamble transmission counter and, whenpossible, a PRACH transmission power. In Step 3, a UE transmits Msg3 ina PUSCH where the Msg3 can include a TC-RNTI. The exact contents of Msg3depend on the state of the UE and in particular on whether or not the UEis previously connected to the eNB. In Step 4, the eNB transmits acontention-resolution message to the UE in a PDSCH. Step 4 also resolvesany contention issue that can arise when multiple UEs try to access anetwork using a same RA preamble. Once a random access process issuccessful, the TC-RNTI is converted to C-RNTI. Step 1 usesphysical-layer processing specifically designed for a random accessprocess. The subsequent three steps utilize a same physical-layerprocessing as for PDSCH or PUSCH transmissions after a UE hasestablished communication with an eNB where Step 2 does not use HARQretransmissions while Step 3 and Step 4 can use HARQ retransmissions.

Contention-free random access is for a UE to establish synchronizationwith a cell having a different timing advance group (TAG) than a cellwhere the UE has synchronized UL transmissions, for reestablishing ULsynchronization upon DL data arrival, for handover, and for positioning.Only Step 1 and Step 2 of the random access process described above areused as there is no need for contention resolution in a contention-freescheme where Step 2 can deliver C-RNTI instead of TC-RNTI.

FIG. 16 illustrates four examples of PRACH formats according to thisdisclosure. The embodiment shown in FIG. 16 is for illustration only.Other embodiments could be used without departing from the scope of thepresent disclosure.

In each PRACH format, there is a cyclic prefix (CP) 1601, a preamblesequence 1602, and a guard time (GT) 1603. Each preamble sequence has alength of 0.8 milliseconds (ms). In format 0 410, both CP and GT areequal to approximately 0.1 ms. In format 1 1620, the CP and GT arerespectively 0.68 ms and 0.52 ms. In format 2 1630 and format 3 1640,the preamble is repeated once to provide energy gain. In format 2, bothCP and GT equal approximately 0.2 ms. In format 3, the CP and GT arerespectively 0.68 ms and 0.72 ms. An additional PRACH format, referredto as format 4, exists and is transmitted over two SF symbols in an ULpilot time slot (UpPTS) region of a special SF in time division duplex(TDD) systems.

FIG. 17 illustrates an example for PRACH transmission from a UEaccording to this disclosure. The embodiment shown in FIG. 17 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

A RA preamble with length N_(ZC) 1710 is processed by an inverse fastFourier transform (IFFT) 1720. The RA preamble is repeated based on apreamble format 1730 when the preamble format is 2, or 3. For preambleformat 0 or 1, the RA preamble is not repeated. CP is inserted 1740prior to the RA-preamble and up-sampling 1750 is subsequently applied.Finally, a time domain frequency shift 1760 is applied and a signal istransmitted by a radio frequency (RF) 1770 component of a UE.

FIG. 18 illustrates an example for PRACH detection at an eNB accordingto this disclosure. The embodiment shown in FIG. 18 is for illustrationonly. Other embodiments could be used without departing from the scopeof the present disclosure.

A received signal 1805 is first processed by CP removal unit 1810 andsubsequently a discrete Fourier transform (DFT) is applied by DFT filter1815 follow by RE de-mapping by demapper 1820 to obtain the REs of a RApreamble transmission. Correlation with a replica of a RA preamble thatis the conjugate of the DFT 1830 of ZC root sequence 1825 is thenapplied by correlator 1840. For contention-based PRACH transmissions,the ZC sequence 1825 can be each of the available sequences. Zeropadding 1845 is applied to the correlator output, the result isprocessed by inverse DFT (IDFT), the energy of the IDFT output isobtained 1855 and finally a sequence detection unit 1860 determineswhether a RA preamble was transmitted based on a detected energy for arespective sequence where, for example, a sequence 1825 resulting alargest energy, or an energy above a threshold, can be considered asdetected. When there are multiple receiver antennas, respective receivedsignals can be combined 1855 before sequence detection 1860.

From a physical layer (L1) perspective, a random access process includesa transmission of an RA preamble and a RAR. Remaining messages arescheduled by higher layers on a PDSCH or a PUSCH and may not beconsidered as part of L1 random access process. The following steps 1 to6 are required for a L1 random access process:

Step 1. A L1 RA process triggered upon a request of a preambletransmission by higher layers.

Step 2. A RA preamble index, a target PRACH received power(PREAMBLE_RECEIVED_TARGET_POWER), a corresponding RA-RNTI and a PRACHresource indicated by higher layers as part of the request.

Step 3. An PRACH transmission power P_(PRACH) is determined as:P _(PRACH)=min{P _(CMAX),(i),PREAMBLE_RECEIVED_TARGET_POWER+PL _(c)}[dBm],where P_(CMAX); (i) is a configured UE transmit power for SF i of cell c(see also REF 3), PL_(c) is a DL path-loss estimate calculated in a UEfor cell c, and PREAMBLE_RECEIVED_TARGET_POWER is a target receivedpower.

Step 4. An RA preamble sequence selected from an RA preamble sequenceset using the preamble index or indicated by a PDCCH order.

Step 5. A single preamble transmitted over 6 RBs using the selectedpreamble sequence with transmission power P_(PRACH) on the indicatedPRACH resource.

Step 6. Detection of a PDCCH with indicated RA-RNTI attempted during aRAR window controlled by higher layers. When detected, a correspondingtransport block is passed to higher layers that parse the transportblock and indicate an UL grant to the physical layer. This is referredto as RAR grant.

For a L1 random access process, an UL transmission timing for a UE afteran PRACH transmission is as follows:

a. When a PDCCH with associated RA-RNTI is detected in SF n and acorresponding transport block in a PDSCH contains a response to atransmitted RA preamble sequence, a UE shall, according to informationin the response, transmit a transport block in a PUSCH in a first SFn+k₁, k₁≥6, when a UL delay field in RAR is set to zero where n+k₁ is afirst available UL SF for PUSCH transmission. The UE shall postpone aPUSCH transmission to a next available UL SF after n+k₁ when the ULdelay field is set to 1.

b. When a RAR is received in SF n and a corresponding transport block ina PDSCH does not contain a response to a transmitted preamble sequence,a UE shall, when requested by higher layers, transmit a new RA preamblesequence no later than in SF n+5.

c. When no RAR is received in SF n, where SF n is a last SF of a RARwindow, a UE shall, when requested by higher layers, transmit a newpreamble sequence no later than in SF n+4.

In case a random access procedure is initiated by a PDCCH order in SF n,a UE shall, when requested by higher layers, transmit an RA preamble ina first SF n+k₂, k₂≥6, where a PRACH resource is available. When a UE isconfigured with multiple TAGs and when the UE is configured with acarrier indicator field (CIF) that is included in a DCI format conveyedby a PDCCH to identify an intended cell, the UE shall use the CIF valuefrom the detected PDCCH order to determine the cell for a correspondingPRACH transmission.

Once a UE transmits a PRACH, and regardless of a possible occurrence ofa measurement gap, the UE shall monitor a PDCCH for RAR scheduling. Sucha PDCCH is identified by a RA-RNTI in a RAR window that starts at a SFthat contains the end of a PRACH transmission plus three SFs and haslength of ra-ResponseWindowSize SFs as configured by higher layers. ARA-RNTI associated with a PRACH is computed as:RA-RNTI=1+t_id+10*f_idwhere t_id is an index of a first SF of a specified PRACH (0≤t_id<10)and f_id is an index of a specified PRACH within that SF, in ascendingorder of frequency domain (0≤f_id<6). For a FDD system, f_id=0. A UE canstop monitoring for RAR(s) after successful reception of a RARcontaining an RA preamble identifier that matches a transmitted RApreamble.

When using an unlicensed frequency band for communication between an eNBand a UE, such communication can often have to satisfy regulatoryrequirements for using the unlicensed frequency band. A firstrequirement can be that a transmission from either the eNB or the UEoccupies at least eighty percent (80%) of an available BW on theunlicensed frequency band. A second requirement can be that atransmission power per megahertz (MHz), also referred to as powerspectral density (PSD), does not exceed a predefined value such as 10 or13 deciBell per milliwatt (dBm). Additional requirements can also exist.For example, a third requirement can be that prior to transmitting in anunlicensed frequency band, an eNB or a UE perform a listen before talk(LBT) procedure to contend for access to the unlicensed frequency band.An LBT procedure can include a clear channel assessment (CCA) procedureto determine whether or not a channel in the unlicensed frequency bandis available. When the CCA determines that the channel is not available,for example because it is used by another device such as a WiFi device,the eNB or the UE can apply an extended CCA procedure to increase alikelihood of gaining access to the unlicensed frequency band. Anextended CCA procedure includes a random number of CCA procedures (from1 to q) according to an extended CCA counter. Each CCA procedure caninclude detecting an energy level on the channel of the unlicensedfrequency band and determining whether or not the energy level is belowa threshold. When the energy level is at or below the threshold, the CCAprocedure is successful and the eNB or the UE can access the channel.When the energy level is above the threshold, the CCA procedure isunsuccessful and the eNB or the UE cannot access the channel.

A maximum PSD requirement can result to a limited coverage fortransmission from a UE to an eNB when using an unlicensed frequencyband. Typically, a maximum UE transmission power can be 23 dBm but a UEneeds to reduce it, for example to 10 dBm, when the UE transmits asignal with continuous BW occupation over 1 MHz. One way to satisfy amaximum PSD requirement while avoiding materially compromising ULcoverage is for a UE to transmit a signal having a discontinuous BWoccupation. For example, a UE can transmit an UL channel, such as aPUSCH or a PUCCH, over one or more RBs that are interleaved throughout aBW of an unlicensed frequency band so that the PSD in the one or moreRBs, each RB spanning 180 KHz, can be 23 dBm but the PSD per MHz can beless that the maximum value specified by regulations. For example, for aBW of 20 MHz corresponding to 100 RBs, when a UE transmits an UL channelin one RB every ten RBs and the maximum PSD requirement is 10 dBm oversix RBs (1.08 MHz), the UE can transmit the UL channel with a PSD of 2.2dBm per RB or 22.2 dBm over the ten discontinuous RBs.

As unlicensed frequency bands cannot be guaranteed to be available atany time instance and cannot offer seamless mobility support, carrieraggregation (CA) is one possible mechanism to exploit unlicensedfrequency bands while maintaining continuous connectivity through alicensed band. A band can also be referred to as a carrier or as a celland CA operation for a UE can include communication on both one or morelicensed cells and one or more unlicensed cells.

Random Access in Unlicensed Carriers

FIG. 19 is a diagram illustrating a communication using CA according tothis disclosure. The embodiment shown in FIG. 19 is for illustrationonly. Other embodiments could be used without departing from the scopeof the present disclosure.

A UE 1910, communicates with a first cell 1920 corresponding to amacro-cell using a first carrier frequency f1 1930 and with a secondcell 1940 corresponding to a small cell over carrier frequency f2 1950.The first carrier frequency can correspond to a licensed frequency bandand the second carrier frequency can correspond to an unlicensedfrequency bad. The first cell and the second cell are connected over abackhaul that introduces negligible latency.

As a distance from a UE to a first cell can be different than a distancefrom the UE to a second cell, the UE needs to apply a different timingadvance command for transmissions to the first cell than fortransmission to the second cell. A group of cells that includes aprimary cell (PCell) and requires a first timing advance (TA) arereferred to as a primary timing advance group (pTAG) while a group ofsecondary cells that do not belong in the pTAG are referred to assecondary TAG (sTAG). A PDCCH order is typically used to enablecontention-free random access in order for a UE to transmit a PRACH to acell in the sTAG and then obtain a timing advance (TA) command from aRAR message following the PRACH transmission in order for the UE tosynchronize its transmission. Several design aspects need to beaddressed for a random access process on an unlicensed cell in order tofulfill regulatory requirements and coexist with other UL transmissionsthat can be over clusters of RBs as in FIG. 9.

A design aspect results from a need to satisfy a regulatory requirementfor a maximum transmission power per MHz while providing a PRACHstructure that can avoid a coverage loss associated with limitations inthe maximum transmission power of the UE.

A second design issue relates to enabling a coexistence among PUSCH orPUCCH transmissions having an interleaved RB structure and a PRACHtransmission over a number of contiguous RBs such as 6 RBs.

A third design issue is to improve a probability for a PRACHtransmission considering that an intended unlicensed cell that isindicated by a PDCCH order can be unavailable at a time of the PRACHtransmission.

A fourth design issue is to improve a probability for a successful RARtransmission in response to a PRACH transmission on an unlicensed cell.

Therefore, there is a need to design a PRACH transmission structure thatenables increased coverage while satisfying a regulatory requirement fora PSD.

There is another need to support coexistence of UL transmissions using awaveform of interleaved RBs and of a PRACH transmission over a number ofcontiguous RBs.

There is another need to increase a probability of a PRACH transmissionon a sTAG with unlicensed cells.

Also, there is another need to increase a probability of a RAR receptionassociated with PRACH transmission on one or more unlicensed cells.

The following descriptions primarily consider contention-free randomaccess but general aspects for a random access process, includingcontention-based random access, are also considered.

PRACH Structure for Increase Coverage in an Unlicensed Cell

A PRACH needs to be able to provide time accuracy in the range of 3microseconds. For example, for TDD operation, a typical requirement isfor synchronization of +/−1.5 microseconds. Even a tightersynchronization requirement, such as +/−0.5 microseconds, is required toenable positioning or coordinated multi-point (CoMP). A PRACHtransmission over 6 RBs, corresponding to a BW of 1080 KHz, cantheoretically provide a timing accuracy that is inversely proportionalto the transmission BW or equivalently about +/−0.5 microseconds.Considering an existence of UEs with low signal-to-interference andnoise ratios (SINR), a timing accuracy within +/−1.5 microseconds can beobtained for practically all UEs in a cell.

PRACH transmissions on an unlicensed cell need to achieve a same levelof time estimation accuracy as PRACH transmissions on a licensed cell.This cannot be achieved by a PRACH transmission over a cluster ofinterleaved RB s with large separation, such as in FIG. 9, as a channelmedium cannot be guaranteed to be relatively constant between any twoRBs. Then, an eNB needs to obtain a time estimate over 1 RB and aresulting accuracy is 6 times worse than the one obtained over 6contiguous RBs as for a PRACH transmission on a licensed cell.

A UE communicating on an unlicensed cell is typically limited inmobility and channel coherence in the time domain is larger than thechannel coherence in the frequency domain. Regarding frequencycoherence, for the ETU channel, an root mean square (rms) delay spreadof τ=1 microsecond, the 50% and 90% coherence BWs are respectively1/(5τ) and 1/(50τ) or 200 KHz and 20 KHz while for the EPA channel, therms delay spread of τ=0.05 microseconds, the 50% and 90% coherence BWsare respectively 4 MHz and 400 KHz. Therefore, when RBs for a PRACHtransmission have a large separation in the frequency domain, it is notpossible for an eNB to perform frequency interpolation of a receivedsignal across RB and the eNB needs to perform cross-correlations todetermine a PRACH arrival time per RB. Regarding time coherence, usingClarke's model for a Doppler frequency of f_(D), the 50% channelcoherence time is √{square root over (9/(16π·f_(D) ²))}. For a UE speedof 30 kilometers per hour, the 50% channel coherence time is ˜1.7milliseconds while a minimum sampling interval (in theory) toreconstruct the channel is 1/(2·f_(D)) or 3 milliseconds and both aresubstantially larger than the SF symbol duration of about 71.4microseconds. Therefore, time-domain interpolation over a few SF symbolscan be performed while frequency domain interpolation over RBs separatedby about 1 MHz or more cannot be performed.

For relatively small cell sizes, such as ones with radius up to 1.4 Km,PRACH format 4 can be used. Transmission can be in 2 SF symbols and theUpPTS part of a special SF can be used. However, as the PRACH needs tobe transmitted over 6 consecutive RBs, whenever regulatory requirementsneed to be satisfied, the maximum PSD needs to be in the range of 10dBm/MHz and this can significantly limit coverage even for small cellsizes due to shadowing. The coverage loss can be compensated byrepetitions of the PRACH format 4 over one SF. With 6 repetitions overone SF of 14 symbols (two SF symbols are not used for repetitions inorder to allow for CCA and possibly SRS transmission) the coverage gainis about 8 dB and, combined with an additional about 4 dB gain due tofrequency diversity, can provide a similar coverage on an unlicensedcell for a maximum UE transmission power of 10 dBm/MHz as on a licensedcell for a maximum UE transmission power of 23 dBm/MHz (or 23 dBm per1.08 MHz for 6 RBs).

FIG. 20 illustrates repetitions of a PRACH format 4 transmission oversix of the twelve symbols of a SF that includes fourteen symbolsaccording to this disclosure. The embodiment shown in FIG. 20 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

For a PRACH format 4 transmission with repetitions in the time domainover one SF, an effective transmission duration is same as for a singlePRACH format 0 and therefore a same channel access priority class canapply.

For larger cell sizes, such as ones with radius between about 1.4 Km and14 Km, a longer PRACH duration of about one SF is needed such as onebased on PRACH format 0. Then, an associated propagation delay and timeuncertainty can be accommodated through a longer GT. Considering that itis desirable to minimize an orthogonality loss in the frequency domainbetween PRACH REs and surrounding PUSCH REs, an RE spacing for PUSCHneeds to be an integer multiple of the RE spacing for the PRACH. For a15 KHz RE spacing for the PUSCH, an RE spacing for a new PRACH formatcan be same as for PRACH format 0 and equal to 1.25 KHz resulting to anRA preamble sequence length of 800 microseconds or equal to 2.5 KHzresulting to an RA preamble sequence length of 400 microseconds.

For PRACH duration of 13 SF symbols (928 microseconds), 128 microsecondsneed to be allocated to the CP duration and the GT duration. To maximizecoverage for a maximum delay spread of 6 microseconds, the CP durationis (928−800)/2+6/2=67 microseconds, a resulting GT duration is 61microseconds and a supportable cell radius of (3e8×61e-6)/2=9.15 Km.Then, a CP duration can be 2048 samples and a GT duration can be 1884samples, or 1856 samples for an integer multiple of 64, where a sampleduration is 1/30.72 microseconds. For PRACH duration of 12 SF symbols or857 microseconds, 57 microseconds need to be allocated to the CPduration and the GT duration. For CP duration of 31 microseconds, aresulting GT duration is 26 microseconds and a supportable cell radiusof (3e8×26e-6)/2=3.9 Km.

As a supportable cell radius materially reduces when reducing a PRACHtransmission period to less than one SF, it is beneficial to considersequence lengths shorter than 800 microseconds and CP and GT durationsabove 100 microseconds while maintaining a RE spacing for the PRACH thatis an integer sub-multiple of the RE spacing of 15 KHz assumed for otherUL transmissions. For a RE spacing of 2.5 KHz, a RA preamble sequencelength is 400 microseconds. A ZC sequence of length (prime number) inthe range of 400 can be used, such as for example 409, 419, 421, 431,and so on. For CP duration of 231 microseconds, GT duration can be 226microseconds and a supportable cell radius is (3e8×226e-6)/2=33.9 Km.Similar, for a PRACH transmission over a partial SF of 1 slot (500microseconds), a CP duration can be (500−400)/2+6/2=53 microseconds, aGT duration can be 47 microseconds, and a supportable cell radius is(3e8×100e-6)/2=15 Km. However, even though the supportable cell radiusincreases, a supportable cell coverage decreases by 3 dB and the RApreamble sequence length decreases by a factor of 2. Repetitions in thefrequency domain such as over multiple sub-bands of 6 RBs or in the timedomain such as over two or more SFs can be considered to recover the 3dB loss in coverage and provide additional coverage. A modified PRACHformat 0, referred to as PRACH format 5, is transmitted over 12 SFsymbols or 13 SF symbols.

For power limited UEs, one approach to overcome a coverage loss from aregulatory PSD constraint regarding a maximum transmission power per MHzand avoid transmitting a PRACH over substantially the whole system BW,is to modify the PRACH transmission structure to be intermittent infrequency per SF symbol. A UE can concentrate a PRACH transmission powerin some of the 6 RBs per SF symbol by nulling REs for the other RBs. AneNB can reconstruct the PRACH transmission over the 6 RBs by combiningindividual transmissions per RB in each of the 6 RBs.

FIG. 21 illustrates a first example for a modified PRACH transmissionstructure over 12 SF symbols according to this disclosure. Theembodiment shown in FIG. 21 is for illustration only. Other embodimentscould be used without departing from the scope of the presentdisclosure.

A PRACH transmission is over SF symbols {0, 3, 6, 9, 12} in a first RBand in a fourth RB associated with RB cluster 0 2110 and RB cluster 32140, respectively, over SF symbols {1, 4, 7, 10} in a second RB and ina fifth RB associated with RB cluster 1 2120 and RB cluster 4 2150,respectively, and over SF symbols {2, 5, 8, 11} in a third RB and in asixth RB associated with RB cluster 2 2130 and RB cluster 5 2160,respectively. It is also possible for a UE to not transmit the PRACH inSF symbol number 13, depending on a design for a LBT observationinterval and possible SRS transmissions. Although the PRACH transmissionis shown to not occur in the last SF symbol, the PRACH transmission caninstead not occur in the first SF symbol when CCA and LBT occur in thefirst SF symbol.

The PRACH transmission structure in FIG. 21 can be beneficial to acoverage limited UE. For a non-coverage limited UE or, in general, forany UE when some coverage loss can be acceptable or can be compensatedby time diversity from additional PRACH transmissions, either byseparate respective PDCCH orders or by a single PDCCH order alsoindicating a number of PRACH transmissions in time, the PRACH repetitionstructure can be same as on an licensed cell over 6 consecutive RBs butalso repeat in the frequency domain to provide for repetition gain andfrequency diversity gain. For example, in case of two repetitions in thefrequency domain, such a transmission structure can provide about a 7 dBgain and overcome most of the coverage loss associated with a regulatoryPSD constraint.

To maximize frequency diversity, two repetitions of a PRACH transmissioncan be located at the two edges of the system BW as there is either noPUCCH region on an unlicensed cell or a PUCCH is transmitted similar toa PUSCH using an interleaved structure over one or more RB clusters.This also results to different clusters of RBs that can be used forPUSCH or PUCCH transmissions being affected by the PRACH transmission.Alternatively, in order to ensure that some RB clusters do not have anyoverlapping RBs with repetitions of a PRACH transmission, the same RBclusters can be used for the repetitions of the PRACH transmission. Forexample, only clusters 1 to 6 or only clusters 5 to 10 can be used forrepetitions of a PRACH transmission and this can be predetermined in thesystem operation, or configured to UEs by higher layers, or dynamicallyindicated by a UE-common DCI format or by the DCI format correspondingto the PDCCH order. In this manner, remaining RB clusters can be ensuredto be free of PRACH transmission and this can be beneficial fortransmission of information requiring enhanced reliability, such as UCI,that can be configured to occur in the remaining clusters of RBs.

FIG. 22 illustrates a PRACH transmission with two repetitions in thefrequency domain during a same SF for a PRACH format based on PRACHFormat 0 according to this disclosure. The embodiment shown in FIG. 22is for illustration only. Other embodiments could be used withoutdeparting from the scope of the present disclosure.

The PRACH transmission is repeated at the two edges of a system BW. Afirst repetition is over a first 6 RBs of the system BW 2210 and asecond repetition is over a last 6 RBs of the system BW 2220. Forexample, for a system BW of 100 RBs and 10 clusters of RBs with 10 RBsper cluster, the first repetition is over one RB for each of the first 6clusters and the second repetitions in over one RB for each of the last6 clusters. As each cluster of RBs can be used for PUSCH or PUCCHtransmissions, the PRACH transmission structure in FIG. 22 minimizes anumber of clusters where a PUSCH or PUCCH transmission needs to bepunctured in order to accommodate a repetition of a PRACH transmissionas only the clusters with index 5 and 6 have 2 RBs used for the PRACHtransmission while the remaining clusters have 1 RB used for the PRACHtransmission.

An indication for a PRACH transmission structure, for example betweenthe ones in FIG. 21 and FIG. 22, can be provided by the DCI formatconveying the PDCCH order or can be configured to a UE from an eNB byhigher layer signaling, for example depending on whether or not the UEis power limited as the eNB can determine, for example, from a measuredreceived signal power or from a power headroom report from the UE.

A PDCCH order from an eNB to a UE can include information for a numberof PRACH repetitions from the UE that the eNB can determine, for examplebased on a received signal power or on a power headroom report from theUE. The frequency locations for the PRACH repetitions can be derivedfrom the number of PRACH repetitions, as it is next described, or can beindicated by the DCI format conveying the PDCCH order or by a UE-commonDCI format.

Let N_(RB) be a number of RBs in a system bandwidth where the RBs areindexed in ascending frequency order. For a PRACH transmission overN_(PRACH) ^(RB) RBs, such as over N_(PRACH) ^(RB)=6 RBs, there are atotal of N_(SB)=└N_(RB)/N_(PRACH) ^(RB)┘ sub-bands of N_(PRACH) ^(RB)RBs in the system bandwidth. The N_(RB)−└N_(RB)/N_(PRACH)^(RB)┘·N_(PRACH) ^(RB) RBs that do not belong in a sub-band can belocated at the two edges of the system bandwidth in an alternatingmanner starting, for example, from the lowest RB index, or can belocated in the middle of the system bandwidth.

In a first approach, for a PRACH transmission with R_(PRACH)repetitions, the repetitions can be in sub-bands with respective indexesn_(SB)=(n_(SB,0)+i·└N_(BB)/N_(PRACH)┘)mod N_(SB), where i=0, 1, . . . ,R_(PRACH−1). The sub-band for the first repetition, n_(SB,0), can be thefirst of the N_(SB) sub-bands (n_(SB,0)=0), or can be configured to a UEby an eNB through higher layer signaling, or can be pseudo-random and,for example, determined as N_(ID) ^(cell) mod N_(SB) where N_(ID)^(cell) is a physical identity for the eNB.

In a second approach, the sub-bands for R_(PRACH) repetitions of a PRACHtransmission can be defined relative to each edge of the systembandwidth and N_(SB) ^(1,2)=└N_(RB)/(2·N_(PRACH) ^(RB))┘ sub-bands areindexed in ascending frequency order from the low end of the system BWand in descending frequency order from the high end of the systembandwidth. PRACH repetitions with even indexes can be in respectivesub-bands with indexes n_(SB)=(n_(SB,0)+i·└N_(SB)/R_(PRACH)┘)mod N_(SB),where i=0, 2, . . . , R_(PRACH)−1, and PRACH repetitions with oddindexes can be in respective sub-bands with indexesn_(SB)=(N_(SB)−n_(SB,0)−(i−1)·└N_(SB)/N_(PRACH) ^(RB)┘)mod N_(SB), wherei=1, 3, . . . , R_(PRACH)−1.

For a PRACH transmission on a licensed cell, from the 864 REs withspacing of 1.25 KHz allocated to PRACH transmission, only 839 REs areused while the remaining 25 REs provide a guard-band of 12.5 REs fromeach side of the PRACH transmission BW in order to mitigate interferencefrom surrounding PUSCH transmissions as the RE spacing (1.25 KHz) of aPRACH transmission is different than the RE spacing (15 KHz) of a PUSCHtransmission. For a PRACH transmission on an unlicensed cell, thetransmission can be at the two edges of the system BW. A guard band cantherefore be placed only in the interior of the system BW to provideincreased protection to the PRACH transmission from data interferenceand the size of the guard band can be double the one for a PRACHtransmission on a licensed cell.

FIG. 23 illustrates a placement of guard-bands for a PRACH transmissionon an unlicensed cell when the PRACH is transmitted at either or bothedges of a system BW. The embodiment shown in FIG. 23 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

A PRACH transmission from a UE is located either at a lower edge of asystem BW 2310 or at a higher edge of the system BW 2320, or both incase the PRACH transmission is with repetitions in the system BW. APRACH is transmitted over a number of consecutive REs, such as 839 REs,2330 or 2335, that include the first RE or the last RE in the system BW,respectively. A number of additional REs, such as 25 REs, are all placedtowards the interior of the system BW, 2340 or 2345, after the REsallocated to the PRACH transmission.

Coexistence of PRACH Transmissions and PUSCH/PUCCH Transmissions on anUnlicensed Cell

As a PRACH transmission overlaps with RBs from one or more clusters ofRBs allocated to PUSCH or PUCCH transmissions, a UE configured totransmit PUSCH or PUCCH over a number of clusters of RBs that includesome of the one or more cluster of RBs needs to be informed of anexistence of a PRACH transmission in order to perform appropriate ratematching and exclude RBs used for PRACH transmission from RBs used totransmit the PUSCH or PUCCH.

In a first example, since a non-contention based PRACH transmission isdynamic as triggered by a PDCCH order, it is beneficial to alsodynamically indicate to UEs an upcoming PRACH transmission through aUE-common DCI format that is decoded by all UEs communicating on a sameunlicensed cell. Given that a PDCCH order in SF n triggers a PRACHtransmission in a first available SF n+k₂, k₂≥6, the UE-common DCIformat informing UEs of upcoming PRACH transmissions can be transmittedin SF n or in a later SF. For transmissions on an unlicensed cell thatincludes a series of DL SFs, followed by a special SF (partial DL SF,GP, partial UL SF), and then followed by a series of UL SFs prior to anext DL SF, when any, a DCI format informing of an upcoming PRACHtransmission can be same as a UE-common DCI format, with size equal to asize of DCI Format 1C, that informs at least of a configuration for anumber of DL symbols and a number of UL symbols in the special SF (seealso REF 2 and REF 3).

When a possible SF for a PRACH transmission is predetermined, such as afirst normal UL SF after a series of DL SFs, when any, or the sixth orseventh SF for a maximum channel occupancy time (MCOT) of ten SFs, andso on, the UE-common DCI format needs to include only one bit toindicate whether a PRACH transmission is expected in the SF. When apossible UL SF for a PRACH transmission is not predetermined, theUE-common DCI format can include an indication of the UL SF (SF offsetrelative to the SF of the UE-common DCI format transmission). Forexample, for a maximum number of 8 continuous normal UL SFs in an MCOTof 10 SFs and use of only one SF for PRACH transmission per MCOT, theindication in the UE-common DCI format can be by 3 bits that provide aSF number from the 8 SFs. When multiple SFs can be available for a PRACHtransmission, the indication can be by a bit-map when a number ofavailable SFs is not predetermined or can include a combinatorialmapping when a number of available SFs is predetermined. This signalingmechanism for indicating available SFs for a PRACH transmission can beapplicable to both contention-based and contention-free PRACHtransmissions.

FIG. 24 illustrates a mechanism for indicating an SF for a PRACHtransmission according to this disclosure. The embodiment shown in FIG.24 is for illustration only. Other embodiments could be used withoutdeparting from the scope of the present disclosure.

An eNB transmits a PDCCH order 2402 in a first SF 2410 of ten SFscorresponding to an MCOT. The eNB transmits a UE-common DCI format 2404in a second SF 2415 that indicates that PRACH transmission is enabledduring the MCOT. Although the PDCCH order transmission is shown in thefirst SF 2410, it can instead or also be in the second SF 2415. TheUE-common DCI format can also include indication for a number of DL SFsymbols and a number of UL SF symbols in a third SF 2420 and alsoinclude an indication for a number of UL SFs following the third SF2420. A UE that detects the UE-common DCI format and is scheduled aPUSCH transmission in SF 2433 that includes one or more RBs that can beused for PRACH transmission, does not transmit the PUSCH in the one ormore RBs and rate matches the PUSCH transmission in remaining allocatedRBs 2406. The RBs available for the PRACH transmission can bepredetermined, for example as in FIG. 22, or can be signaled in a SIB.

In FIG. 24, the SF for the PRACH transmission is either assumed to bepredetermined and derived, for example as the sixth SF in the MCOT often SFs, or is indicated in the UE-common DCI format. For example, a2-bit field can indicate whether the SF for the PRACH transmission isthe fourth, fifth, sixth, or seventh, SF after the SF of the UE-commonDCI transmission, that is, indicate a SF offset after the SF of theUE-common DCI transmission. This implies that a UE that detects thePDCCH order also needs to detect the UE-common DCI format in order todetermine the available SF for PRACH transmission. In that sense, theUE-common DCI format provides system information to UEs. Activation by aUE-common DCI format can also apply, in a similar manner as for a PRACHtransmission scheduled by a PDCCH order, for a PUSCH transmissionscheduled by an UL DCI format.

To further optimize a PRACH transmission in response to a PDCCH order byenabling a UE that detects the PDCCH order and fails to detect theUE-common DCI to be able to transmit the PRACH, the available SF forPRACH transmission can also be indicated in a DCI format conveying thePDCCH order. Moreover, the UE-common DCI can indicate a SF for PRACHtransmission for a next MCOT. For example, this can be applicable whenregulatory requirements mandate an MCOT of only four SFs. The aboveconsider than only one SF per MCOT can be used for PRACH transmissionsbased on respective PDCCH orders. When more than one SF can be used, theUE-common DCI format can include respective signaling to indicate themultiple SFs such as for example a bit-map with size equal to the numberof UL SFs where a bit value of ‘1’ can indicate a SF available for PRACHtransmission.

As an MCOT of an unlicensed cell is limited by regulation, it is alsopossible to shorten the time for triggering a PRACH transmission on anunlicensed cell to be less than 6 SFs after the SF of the PDCCH ordertransmission. For example when a UE detects a PDCCH order in SF n, theUE can be expected to transmit an PRACH in a first available SF n+k₃,k₃≥4.

In a second example, SFs that are available for PRACH transmission aresignaled in a SIB. When a UE determines that a SF indicated as availablefor PRACH transmission in a SIB includes DL transmissions, for exampleby measuring a RS transmitted by an eNB or by detecting a UE-common DCIformat indicating a partitioning of DL SFs and UL SFs in a MCOT, the UEdoes not transmit a PRACH for contention-based PRACH or, forcontention-free PRACH, when the SF satisfies a timing relationship suchas being 6 SFs after a SF where the UE detects a PDCCH order. Moreover,UEs having a PUSCH transmission in a SF indicated as available for PRACHtransmission, rate match the PUSCH transmission by excluding RBs thatcan be used for PRACH transmission.

In a third example, a specification of a system operation predefines anSF within an MCOT, when any, to always include resources for a PRACHtransmission. For example, the SF can be a last SF in a number ofconsecutive UL SFs. A UE transmitting PUSCH or PUSCH in the SF ratematches a respective transmission to exclude RBs that can potentially beused for PRACH transmission by other UEs.

The UE-common DCI format can additionally include information for anumber of repetitions in the frequency domain, each repetition includingN_(PRACH) ^(RB) RBs, for a PRACH transmission. Based on the number ofrepetitions, locations for the respective sub-bands in a systembandwidth can be derived, for example as it was previously described byusing the first approach or the second approach for determining thesub-bands associated with a number of repetitions for a PRACHtransmission. Then, a UE with a PUSCH or PUCCH transmission candetermine RBs that, although allocated for the PUSCH or PUCCHtransmission, are not used to transmit the PUSCH or PUCCH as they can beused for one or more repetitions of the PRACH transmission. For a UEwith a PRACH transmission, a number of repetitions can equal to thenumber of repetitions indicated by the UE-common DCI format or can beindicated by the DCI format conveying the PDCCH order. For example, a2-bit field can be included in a UE-common DCI format or in a DCI formatconveying a PDCCH order and can indicate a number of repetitions, forexample from a set of {1, 2, 4, 8} repetitions or from a set of {2, 4,8, 16} repetitions.

Support of Multiple PRACH Opportunities

When a UE detects a PDCCH order for a PRACH transmission on anunlicensed cell, regulations can require for the UE to perform CCA andLBT prior to the PRACH transmission. When the CCA/LBT fails, the UE doesnot transmit the PRACH. Then, it is highly likely that the eNB fails todetect a PRACH for an associated PDCCH order as there was no actualPRACH transmission. When an unlicensed cell is heavily occupied forcommunication with various devices and an eNB triggers a single PRACHtransmission by a PDCCH order to a UE, the UE can often sense theunlicensed cell as being unavailable (occupied by other transmissions)and the eNB needs to transmit potentially multiple PDCCH orders beforedetecting a PRACH from the UE. This increases an associated DL controlsignaling overhead.

To reduce DL control signaling overhead scheduling PDSCH or PUSCHtransmissions, multi-SF scheduling is typically considered where asingle DCI format schedules a PDSCH transmission to a UE or a PUSCHtransmission from a UE over a number of SFs that are indicated by theDCI format. Unlike multi-SF scheduling for PUSCH or PDSCH transmissionthat always occurs in a number of SFs indicated by an associated DCIformat, a multi-SF PDCCH order is equivalent to a dynamic signalingthrough a DCI format of a parameter preambleTransMax that defines amaximum number of PRACH transmission attempts for a UE. For a licensedcell, the parameter preambleTransMax is only applicable forcontention-based PRACH transmissions and is provided to a UE by higherlayers (see also REF 4 and REF 5). Therefore, a DCI format providing aPDCCH order for a PRACH transmission, or a UE-common DCI format, caninclude a field indicating a new parameter, preambleTransMax_SCell, thatdefines a maximum number of PRACH transmission attempts from a UE.

When a UE detects a PDCCH order, the UE attempts to transmit a PRACH ina first UL SF indicated as being available for PRACH transmission andsatisfying a timing relation relative to the SF of the PDCCH order, suchas for example being at least 6 SFs later. When the UE succeeds intransmitting the PRACH, the UE attempts to detect a RAR within a RARwindow. The eNB configures the UE with a RAR window size in number ofSFs. The eNB can separately configure a RAR window for licensed cellsand a RAR window for unlicensed cells. For contention-free PRACHtransmission triggered by a PDCCH order, a RAR window size can berelatively small as the eNB controls a number of PDCCH orders and fewUEs typically require contention-free PRACH transmission during a periodof a few SFs. When the UE detects a RAR in response to a RA preambletransmission, the UE does not transmit PRACH for remaining attempts fromthe number preambleTransMax_SCell attempts. The UE autonomously extendsa RAR window after every PRACH transmission. When a RAR transmission ison an unlicensed cell, the UE also autonomously extends a RAR windowdepending on a determination of availability for the unlicensed cell.

FIGS. 25A and 25B illustrate a process for transmitting acontention-free PRACH with multiple transmission opportunities accordingto this disclosure. The embodiment shown in FIGS. 25A and 25B is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

An eNB transmits a PDCCH order and a UE detects the PDCCH order 2510 ina first SF 2515. The DCI format conveying a PDCCH order includes a fieldpreambleTransMax_SCell indicating a maximum of two PRACH transmissionsduring SFs that are indicated as available for PRACH transmission by theDCI format or by a UE-common DCI format. Each SF available for PRACHtransmission can be further conditioned to occur after a number of SFswhere a RAR can be transmitted in response to a previous PRACHtransmission. The UE transmits a PRACH 2520 in a second SF 2525. The UEresets a RAR window, for example to start 3 SFs after the SF of thePRACH transmission when the RAR is transmitted on a licensed cell or ata next MCOT when the RAR is transmitted on an unlicensed cell, andincrements by 1 a counter PREAMBLE_TRANSMISSION_COUNTER that isinitially set to zero 2530. The UE attempts to detect a RAR 2540 duringa third number of SFs 2542, 2544, and 2546 (in a next frame or in a nextMCOT) to determine whether or not the RAR includes an indication for anRA preamble used in the PRACH transmission 2550. When the UE detects aRAR that includes the RA preamble used in a previous PRACH transmissionby the UE, the UE suspends subsequent PRACH transmissions 2560. When theUE does not detect a RAR that includes the RA preamble used in aprevious PRACH transmission by the UE, the UE determines whether or notPREAMBLE_TRANSMISSION_COUNTER is larger than preambleTransMax_SCell2570. When the condition in step 2570 is true, the UE does not transmitany additional PRACH 2580. When the condition in step 2570 is not true,the UE transmits a PRACH during a next available SF 2590 and repeats thesteps after a PRACH transmission. When the UE does not transmit a PRACHdue to sensing the unlicensed cell to be occupied (LBT fails), the UEdoes not increase the PREAMBLE_TRANSMISSION_COUNTER.

To accommodate a regulatory requirement for a maximum PSD of P_(CMAXeg)per MHz, a power for a PRACH transmission from a UE over a contiguousset of 6 RBs in a SF i on an unlicensed cell c, P_(PRACH) ^(U), can bedetermined as:R _(PRACH) ^(U)=min{min(P _(CMACc)(i),P_(CMAXreg)),PREAMBLE_RECEIVED_TARGET_POWER+PL _(c)} [dBm]wherePREAMBLE_RECEIVED_TARGET_POWER=preambleInitialReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_TRANSMISSION_COUNTER−1)and preambleInitialReceivedTargetPower and DELTA_PREAMBLE are parametersconfigured to the UE from an eNB by higher layers.

When a PRACH transmission, from the preambleTransMax_SCell PRACHtransmissions, occurs within a RAR window for a previous PRACHtransmission, the PRACH transmission is with a same power as theprevious PRACH transmission. When a PRACH transmission, from thepreambleTransMax_SCell PRACH transmissions, is after a RAR window of aprevious PRACH transmission, power ramping can apply where a UEincreases a PRACH transmission power by a value (in decibells) providedby a parameter powerRampingStep that is configured to the UE by higherlayers. A transmission power increases by powerRampingStep for a firstPRACH transmission after a RAR window of an earlier PRACH transmissionfrom the multiple PRACH transmissions expires. Therefore, a parameterPREAMBLE_TRANSMISSION_COUNTER used to determine a PRACH transmissionpower is incremented, for the purpose of determining the PRACHtransmission power, only when a RAR window from an earlier PRACHtransmission expires even though there can be other ongoing RAR windowsfrom other previous PRACH transmissions occuring after the earlier PRACHtransmission.

To simplify an operation associated with multiple PRACH transmissionopportunities, a PRACH transmission opportunity can be restricted tooccur only after a RAR window for an immediately previous PRACHtransmission opportunity expires, even when SFs available for PRACHtransmissions exist within the RAR window. Then, power ramping for PRACHtransmissions as described in REF4 can apply and a UE increments aPREAMBLE_TRANSMISSION_COUNTER after each PRACH transmission, when the UEdoes not receive a RAR for a previous PRACH transmission, untilPREAMBLE_TRANSMISSION_COUNTER reaches a value provide by apreambleTransMax_SCell parameter.

A single PDCCH order can also be valid over a number of cells thatbelong to a same sTAG. Even when a UE cannot simultaneously transmit inmore than one cell at a same time, PRACH transmission opportunities ondifferent cells can be staggered in time. For example, a first UE-commonDCI format transmitted on a first cell can indicate a different SF asbeing available for a PRACH transmission that a second UE-common DCIformat transmitted on a second cell. By providing to a UE multipleopportunities for a PRACH transmission on respective multiple cells, aprobability that the UE is able to transmit PRACH or the eNB is able todetect PRACH in at least one of the multiple cells is improved, forexample as a probability of at least one respective LBT succeeding isimproved. However, an overall latency for a contention-free randomaccess, and for a contention-based random access, depends on both alatency for a UE to transmit a PRACH and a latency for an eNB totransmit an associated RAR. Therefore, when a PDCCH order is valid overa number of cells, it is beneficial to remove a constraint for the RARtransmission to be on the same (licensed or unlicensed) cell as thePDCCH order transmission and instead also include all cells of a sameTAG where the UE can transmit the PRACH.

FIG. 26 illustrates a process for transmitting a PRACH and an associatedRAR according to this disclosure. The embodiment shown in FIG. 26 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

An eNB transmits a PDCCH order to a UE on a first cell 2610. Upondetecting the PDCCH order, the UE transmits the PRACH 2620. Although thePRACH transmission is shown to be on a same cell as the transmission ofthe PDCCH order, this is not necessary. The eNB performs an LBT for thefirst SF of a next MCOT on the first cell and the LBT fails 2630. The UEis also configured for PRACH opportunities on a second cell 2640. TheeNB performs an LBT for the first SF of a next MCOT on the second cell,the LBT succeeds, and the eNB transmits a RAR to the UE 2650 in responseto the PRACH transmission on the first cell.

A number of cells with PRACH transmission opportunities for a UE can beindicated to the UE through several mechanisms. In a first example, eachcell configured for communication to a UE has an index and the DCIformat conveying the PDCCH order can include a number of cells, startingfor example from the cell where an eNB transmits the PDCCH order, wherethe cells are ordered according to an ascending cell index. In a secondexample, the UE can be configured by higher layers the cells thatinclude PRACH transmission opportunities for the UE. In a third example,all cells of a same sTAG that are configured for communication to a UEinclude PRACH transmission opportunities for the UE.

RAR Contents

A RAR typically includes an UL grant scheduling an Msg3 transmissionfrom a UE, a TA command, and a TC-RNTI. Even when Msg3 retransmissionsor, in general, PUSCH transmissions are based on asynchronous HARQ andan UL grant needs to include a HARQ process number field and aredundancy version (RV) number field, these two fields do not need to beincluded in the UL grant of a RAR as the RAR schedules only an initialtransmission of an Msg3 in a PUSCH or of data in a PUSCH and thereforethe HARQ process number is 0 and the RV number is 0.

For an Msg3 transmission in a PUSCH that is interleaved in clusters ofRBs, for example as in FIG. 9 a frequency hopping flag is not needed.Also, only one cluster or two clusters need to be indicated by the ULgrant in the RAR as a transport block size for an Msg3 is sufficientlysmall and a resource allocation of one cluster of RBs is sufficient.Therefore, assuming for example ten RB clusters in a system BW, thefirst 10 states of the 16 states of a RB assignment field that includes4 bits can indicate one of the ten clusters while the remaining 6 statescan indicate the pairs of clusters {0, 5}, {1, 6}, {2, 7}, {3, 8}, {4,9} and the triplet of clusters {0, 4, 9} or {0, 5, 9}. Alternatively,the last state or possibly additional states can indicate whether the UEtransmits a PUSCH in a partition of a cluster such as only on evenindexed RBs or on odd index RBs of an indicated cluster. This can reducethe minimum RB allocation to half a cluster and allow multiplexing oftwo UEs in a cluster, and it can be beneficial for small data transportblock sizes such as ones associated with an Msg3.

Table 2 provides the contents of an UL grant for an Msg3 transmissionfrom a UE on a licensed cell and on an unlicensed cell. A size of one ormore field of the UL grant for transmission on an unlicensed cell can befurther reduced as it is subsequently described.

TABLE 2 Contents of an UL grant for Msg3 transmission UL grant LicensedCell Unlicensed Cell Hopping flag 1 bit 0 bit RB Assignment 10 bits 4bits MCS 4 bits 4 bits TPC command 3 bits 3 bits UL delay 1 bit 1 bitCSI-request 1 bit 1 bit

From Table 2 it is observed that a size of an UL grant in a RAR for anMsg3 transmission on an unlicensed cell can be about 13 bits while asize of an UL grant in a RAR for Msg3 transmission on a licensed cell is20 bits. Moreover, a size of a TA command in a RAR for an Msg3transmission on a licensed cell is 12 bits allowing coverage over a cellwith size of 100 kilometers. The RAR is transmitted in octets as a MACpacket data unit (PDU). One octet can include bits for both the TAcommand and the UL grant. A TA command and an UL grant for an Msg3transmission on a licensed cell are conveyed by 4 octets (32 bits). Itis therefore possible to reduce to 3 a number of octets required toconvey an UL grant and a TA command for an Msg3 transmission on anunlicensed cell either by reducing the TA command by one or more bits orby reducing the UL grant in Table 1 by one or more bits, or both.

A size for a TA command size for an Msg3 transmission on an unlicensedcell can be reduced to 11 bits by limiting communication support to cellsizes of about 50 kilometers. This does not have a material impact astypical sizes for unlicensed cells are much smaller than 50 kilometers.The UL grant size can also be further reduced by interpreting its fieldsdepending on whether the associated random access process iscontention-free or contention-based. For example, the CSI-request fieldis only needed for contention-free random access and can be excluded forcontention-based random access. For example, the UL delay field ismostly beneficial for contention-based random access and can be excludedfor contention-free random access. In this manner, a size of the ULgrant in a RAR is reduced by 1 bit relative to the size in Table 1.Further, the interpretation of the RB assignment can be different. Forcontention-based random access, a PUSCH transmission scheduled by an ULgrant in the RAR conveys an Msg3 and a RB assignment can be aspreviously discussed. For contention-free random access, a PUSCHtransmission scheduled by an UL grant in the RAR conveys data associatedwith a connection to the SCell (handover) and the RB assignment can havea mapping allocating a larger number of clusters.

FIGS. 27A and 27B illustrate a size of a RAR message with respect to theoctets used to provide a TA command and an UL grant for contention-basedrandom access and for contention-free random access according to thisdisclosure. The embodiment shown in FIGS. 27A and 27B are forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

For contention-based random access, four octets are used to provide a TAcommand and an UL grant as illustrated in FIG. 27A. For contention-freerandom access, three octets are used to provide a TA command and an ULgrant in FIG. 27B. In the latter case, even though the TA command isshown to include 12 bits and the UL grant to also include 12 bits, adifferent partitioning can also apply and the TA command can include 10bits or 11 bits and the UL grant can include 14 bits or 13 bits.

Transmission of Uplink Control Information for a Cell Group

A UE can be configured with multiple cells on an unlicensed frequencyband and with one cell or a few cells on a licensed frequency band. Astransmissions on a cell of a licensed frequency band are not subject toLBT, the UE can be configured a cell on a licensed frequency band forPUCCH transmissions in order to ensure that the UE can transmit UCI.This cell is referred to as primary cell (PCell). A same PCell on alicensed frequency band is typically configured to multiple UEs therebyincreasing resource requirements on the PCell for supporting PUCCHtransmissions. To alleviate PUCCH resource requirements on a PCell for aUE, the UE can be configured a group of cells for multiplexing aHARQ-ACK codebook in a PUSCH transmission on a cell from the group ofcells, in response to PDSCH receptions on cells from the group of cells,instead of transmitting the HARQ-ACK codebook in a PUCCH on the PCell.This group of cells is referred to as UCI cell group or UCG.

A UCG typically includes cells on unlicensed bands. Therefore, eventhough UCI multiplexing from a UE in a PUSCH transmission on a UCG cellcan alleviate UCI resource overhead on a cell of a licensed band, UCItransmission cannot be guaranteed at a given time instance as the UEneeds to perform a CCA prior to the PUSCH transmission and when the CCA(or the LBT) fails, the UE suspends the PUSCH transmission. Moreover, asa CCA occurs shortly prior to a PUSCH transmission, it is possible thatthe UE does not have sufficient processing time to reconfigure a ratematching for a data transmission and multiplex UCI in another PUSCHtransmission or in a PUCCH transmission. An eNB can be unable todetermine absence of a PUSCH transmission from a UE as a transmissionfrom another device, such as a WiFi device, or even from another UE to adifferent eNB can occur and be a reason for the LBT failure associatedwith the PUSCH transmission.

A DL DCI format can include a counter DL assignment indicator (DAI)field and a total DAI field. For a FDD system, a value of a counter DAIin a DCI format scheduling a PDSCH transmission from an eNB to a UE in acell indicates a number of DL DCI formats transmitted from the eNB tothe UE in a SF and scheduling PDSCH transmissions in cells with indexesup to the cell index while a value of a total DAI field indicates atotal number of DL DCI formats transmitted from the eNB to the UE in theSF. For a TDD system where for a number of successive DL SFs a UEtransmits HARQ-ACK in a same UL SF, a value of the counter DAI in a DLDCI format scheduling a PDSCH transmission counts a number of DL DCIformats an eNB transmits to the UE across cells, according to anascending order of a cell index, and across SFs according to anascending order of the SF index, up to the SF and the cell of the of thePDSCH transmission, while a value of a total DAI field counts a totalnumber of DL DCI formats the eNB transmits up to the SF of the DL DCIformat transmission. For a FDD system, UL DCI formats do not include aDAI and a UE determines a HARQ-ACK codebook for transmission in a PUSCHin a same manner as for transmission in a PUCCH based on the counter DAIvalues and on the total DAI values in associated DL DCI formats. For aTDD system, UL DCI format include a DAI and a UE can determine aHARQ-ACK codebook for transmission in a PUSCH either as for transmissionin a PUCCH or based on the value of the DAI field.

A HARQ-ACK codebook can depend on whether or not a UE detects UL grantsscheduling PUSCH transmissions on UCG cells. When the UE detects ULgrants scheduling PUSCH transmissions on UCG cells, the UE multiplexes aHARQ-ACK codebook for UCG cells in one or more of the PUSCHtransmissions and multiplexes a HARQ-ACK codebook for non-UCG cells in aPUCCH transmission or in a PUSCH transmission on a non-UCG cell.Conversely, when the UE does not detect UL grants scheduling PUSCHtransmissions on UCG cells, the UE multiplexes a HARQ-ACK codebook forboth UCG cells and non-UCG cells in a PUCCH transmission or in a PUSCHtransmission on a non-UCG cell.

Therefore, there is a need to determine a HARQ-ACK codebook when a UE isconfigured a UCG for HARQ-ACK multiplexing on one or more PUSCHtransmissions.

There is another need to enable a transmission of HARQ-ACK codebook whena CCA fails and a UE suspends a PUSCH transmission where the UEmultiplexes the HARQ-ACK codebook.

Finally, there is another need for a UE to inform an eNB of a CCAfailure and of a suspended PUSCH transmission with a multiplexedHARQ-ACK codebook.

In the following, unless otherwise explicitly mentioned, each cell of aUCG that an eNB configures to a UE is assumed to be a cell where the UEneeds to perform CCA prior to PUSCH transmission. This assumption is notrequired for the embodiments of the present disclosure, and some of thecells in the UCG need not require CCA prior to respective PUSCHtransmissions, but the description of the embodiments of the presentdisclosure can be simplified by assuming that the UE needs to performCCA prior to PUSCH transmissions on each respective cell of the UCG.

A UE can be configured with a group of UL cells and with a group of DLcells. Each UL cell from the group of UL cells can be linked to a DLcell from the group of DL cells or there can be one or more UL cellsfrom the group of UL cells not linked to DL from the group of DL cells.The UE can multiplex a HARQ-ACK codebook in response to PDSCH receptionsor in response to an SPS PDSCH release on cells from the group of DLcells to one or more PUSCH transmissions on cells from the group of ULcells. The group of DL cells or UL cells is referred to, respectively,as DL or UL UCI cell group or, without ambiguity, as UCG. For brevity,SPS PDSCH release is not explicitly mentioned in the following but it isassumed that a UE generates HARQ-ACK information in response to adetection, or absence of detection, for a DL DCI format indicating a SPSPDSCH release.

HARQ-ACK Codebook Determination

A configuration of a UCG to a UE can be combined with a configurationfor simultaneous PUSCH transmissions on UCG cells and PUCCH transmissionor PUSCH transmissions on non-UCG cells. Without a capability for a UEto simultaneously transmit PUSCHs on UCG cells and PUCCH on a PCell andassuming that UCI, such as HARQ-ACK information, for non-UCG cells isnot multiplexed in a PUSCH transmission on a UCG cell and thattransmission of HARQ-ACK information for non-UCG cells is prioritizedover transmission of HARQ-ACK information for UCG cells, the UE needs todrop PUSCH transmissions on UCG cells whenever the UE needs to transmitUCI for non-UCG on a PUCCH. When a UE is configured a UCG and the UE hasPUSCH transmissions in UCG cells in a SF, the UE multiplexes HARQ-ACKfor UCG cells in the PUSCH transmissions in the SF. When a UE isconfigured a UCG and the UE does not have PUSCH transmissions in UCGcells in a SF, the UE can multiplex HARQ-ACK for UCG cells on a PUCCH orin a PUSCH transmission on a non-UCG cell in the SF.

When a UE is not configured a UCG, values of DAI fields in respective DLDCI formats scheduling PDSCH transmissions on non-UCG cells and valuesof DAI fields in respective DL DCI formats scheduling PDSCHtransmissions on UCG cells are jointly determined as described in REF 3.When a UE is configured with a UCG, the present disclosure provides twoapproaches for a functionality of a DAI field.

In a first approach, DAI values in DL DCI formats scheduling PDSCHtransmissions on non-UCG cells are independent of DAI values in DL DCIformats scheduling PDSCH transmissions on UCG cells. The first approachcan be combined with an absence or a non-use of a DAI field in UL DCIformats. Having independent DAI values in DL DCI formats for non-UCGcells and for UCG cells enables a UE to determine a first HARQ-ACKcodebook for non-UCG cells and a second HARQ-ACK codebook for UCG cells.The UE uses the first HARQ-ACK codebook for multiplexing HARQ-ACKinformation in a PUSCH on a non-UCG cell and uses the second HARQ-ACKcodebook for multiplexing HARQ-ACK information in a PUSCH on a UCG cell.The UE can use a union of the two HARQ-ACK codebooks for HARQ-ACKmultiplexing in a PUCCH. The union can be as described in REF 3, or thesecond HARQ-ACK codebook can be appended to the first HARQ-ACK codebook,and so on. Moreover, when present, DAI values in UL DCI formatsscheduling PUSCH transmissions on non-UCG cells are independent of DAIvalues in UL DCI formats scheduling PUSCH transmissions on UCG cellswhen a UE is configured a UCG. The UE uses a DAI value in an UL DCIformat scheduling a PUSCH transmission on a non-UCG cell to determine anHARQ-ACK codebook for multiplexing in the PUSCH transmission on thenon-UCG cell and the UE uses a DAI value in an UL DCI format schedulinga PUSCH transmission on a UCG cell to determine an HARQ-ACK codebook formultiplexing in the PUSCH transmission on the UCG cell.

FIG. 28 illustrates an example for a determination of a HARQ-ACKcodebook based on DAI fields in DL DCI formats for UCG cells and non-UCGcells according to this disclosure. The embodiment shown in FIG. 28 isfor illustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

A UE detects DL DCI formats scheduling respective PDSCH transmissions onnon-UCG cells and UCG cells. The UE determines a first HARQ-ACK codebookbased on values of respective DAI fields in detected DL DCI formatsscheduling PDSCH transmissions in non-UCG cells and determines a secondHARQ-ACK codebook based on values of respective DAI fields in detectedDL DCI formats scheduling PDSCH transmissions in UCG cells 2820. ForHARQ-ACK transmission in a PUCCH on a PCell, the UE combines the firstHARQ-ACK codebook and the second HARQ-ACK codebook 2830, for example byeither determining a single HARQ-ACK codebook based on values of DAIfields in DL DCI formats for all cells (non-UCG cells and UCG cells) asdescribed in REF 3 (in that case, step 2820 can be omitted), or byappending the second HARQ-ACK codebook to the first HARQ-ACK codebook.For HARQ-ACK codebook transmission only in a PUSCH on a non-UCG cell,the UE determines a HARQ-ACK codebook either based on a value of a DAIfield in an UL DCI format scheduling the PUSCH transmission or, in casea DAI field in the UL DCI format does not exist, based on a samecombined HARQ-ACK codebook as for transmission in a PUCCH 2840. ForHARQ-ACK codebook transmission only in a PUSCH on a UCG cell, the UEdetermines a HARQ-ACK codebook either based on a value of a DAI field inan UL DCI format scheduling the PUSCH transmission or, in case a DAIfield in the UL DCI format does not exist, based on the second HARQ-ACKcodebook 2850. For HARQ-ACK codebook transmission both in a first PUSCHor a PUCCH on a non-UCG cell and in a second PUSCH on a UCG cell, the UEdetermines a first HARQ-ACK codebook for transmission in the first PUSCHor in the PUSCH 2860 based either on a DAI field in a first UL DCIformat scheduling the first PUSCH transmission or based on the firstHARQ-ACK codebook, for example when the first UL DCI format does notinclude a DAI field, and the UE determines a second HARQ-ACK codebookfor transmission in the second PUSCH 2870 based either on a DAI field ina second UL DCI format scheduling the second PUSCH transmission or basedon the second HARQ-ACK codebook for example when the second UL DCIformat does not include a DAI field. When present, a value of a DAIfield in the first UL DCI format can be different than a value of a DAIfield in the second DCI format.

In a second approach, values of DAI fields in respective DL DCI formatsscheduling PDSCH transmissions on non-UCG cells and values of DAI fieldsin respective DL DCI formats scheduling PDSCH transmissions on UCG cellsare jointly considered. The second approach requires an existence of aDAI field in UL DCI formats. Having values of DAI fields in DL DCIformats jointly consider non-UCG cells and UCG cells is effectivelyequivalent to having a single CG and a HARQ-ACK codebook determinationas described in REF 3 per CG can apply for multiplexing a HARQ-ACKcodebook in a PUCCH. For multiplexing a HARQ-ACK codebook in a PUSCH, avalue of a DAI field in an UL DCI format scheduling a PUSCH transmissionon a non-UCG cell can be independently set from a value of a DAI fieldin an UL DCI format scheduling a PUSCH transmission on a UCG cell.Having values of DAI fields in UL DCI formats being independently setfor non-UCG cells and for UCG cells is effectively equivalent to havingtwo separate CGs for HARQ-ACK codebook determination for transmission ina PUSCH. A first HARQ-ACK codebook is determined from the value of DAIfields in UL DCI formats scheduling PUSCH transmissions in non-UCG cellsand a second HARQ-ACK codebook is determined from the value of DAIfields in UL DCI formats scheduling PUSCH transmissions in UCG cells.Therefore, for HARQ-ACK codebook transmission only in a PUCCH or only ina PUSCH on a non-UCG cell, there is one CG that includes both non-UCGcells and UCG cells while for HARQ-ACK codebook transmission in a PUCCHor a PUSCH on a non-UCG cell and HARQ-ACK codebook transmission in aPUSCH on a UCG cell there are two CGs where the first CG includesnon-UCG cells and the second CG includes UCG cells. A determination ofHARQ-ACK codebooks for each of the above cases can be as in FIG. 7 withthe exception of using a combined codebook determined as in REF 3 forHARQ-ACK codebook transmission in a PUCCH and using a value of DAIfields (all assumed to have a same value) in UL DCI formats schedulingPUSCH transmissions on cells of a UCG for HARQ-ACK codebook transmissionin a PUSCH on a UCG cell while using a value of DAI fields (all assumedto have a same value) in UL DCI formats scheduling PUSCH transmissionson cells of a non-UCG for HARQ-ACK codebook transmission in a PUSCH on anon-UCG cell.

A UE suspends a PUSCH transmission on a cell, such as a UCG cell, when aCCA test the UE performs prior to the PUSCH transmission indicates thatthe channel medium on the cell is occupied by transmissions from otherdevices. With respect to transmission of a HARQ-ACK codebook in a SF, aCCA failure is functionally different than a failure to detect an UL DCIformat scheduling a PUSCH transmission at least because a CCA failureprobability can be materially larger than a probability of a misseddetection for the UL DCI format and because, without prior actions toanticipate a CCA failure, a UE cannot transmit HARQ-ACK codebook onanother channel in the SF as the UE does not have sufficient time toswitch the HARQ-ACK transmission from a PUSCH on the cell to a PUCCH orto a PUSCH on another cell.

A UE implementation can address a probability of CCA failure for a PUSCHtransmission with a multiplexed HARQ-ACK codebook by preparing inadvance an alternative channel to multiplex the HARQ-ACK codebook anduse the alternative channel to transmit the HARQ-ACK codebook in casethe UE does not transmit the PUSCH due to a CCA failure. For example, aUE can prepare in advance a multiplexing of a HARQ-ACK codebook for UCGcells in a PUCCH transmission on a PCell and transmit the PUCCH on thePCell when a CCA for a PUSCH transmission on a UCG cell fails. Forexample, a UE can multiplex a HARQ-ACK codebook for UCG cells in morethan one PUSCH transmissions, when any, on UCG cells. Otherwise, when aHARQ-ACK codebook for UCG cells that the UE multiplexes in a PUSCH theUE is scheduled to transmit on a UCG cell is not also multiplexed onanother channel when a CCA for the PUSCH fails, the UE needs to drop thePUSCH transmission and therefore the transmission of the HARQ-ACKcodebook.

FIG. 29 illustrates an example for a UE to transmit a HARQ-ACK codebookfor UCG cells either in a PUSCH on a UCG cell or on a PUCCH in a PCell.The embodiment shown in FIG. 29 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

A UE detects DL DCI formats scheduling PDSCH transmissions on UCG cellsand UL DCI formats scheduling PUSCH transmission on UCG cells 2910. TheUE performs CCA prior to a PUSCH transmission on a UCG cell where the UEmultiplexes a HARQ-ACK codebook 2920. The UE determines whether the CCAfails 2930. When the CCA does not fail, the UE transmits the PUSCH andmultiplexes the HARQ-ACK codebook 2940. When the CCA fails, the UEtransmits the HARQ-ACK codebook in a PUCCH on a PCell 2950. This can befurther conditioned on the UE having a second HARQ-ACK codebook fornon-UCG cells to transmit in the PUCCH on the PCell and the UE preparinga first version for the PUCCH transmission containing only the secondHARQ-ACK codebook and a second version containing both HARQ-ACKcodebooks and selecting the first version when the CCA does not fail andselecting the second version when the CCA fails.

When a UE fails to detect UL grants for PUSCH transmissions on UCGcells, the UE transmits HARQ-ACK for UCG cells in a PUCCH or in a PUSCHon a non-UCG cell. Therefore, the HARQ-ACK codebook in a PUCCH or in aPUSCH in a SF can depend on whether or not the UE detects UL grantsscheduling PUSCH transmissions on UCG cells in the SF as a PUCCHtransmission can include HARQ-ACK for non-UCG cells when the UE detectsUL grants for PUSCH transmissions on UCG cells and includes HARQ-ACK forall cells when the UE does not detect UL grants for PUSCH transmissionson UCG cells.

An eNB can receive a HARQ-ACK codebook in a PUCCH or in a PUSCH on anon-UCG cell according to a hypothesis that a UE transmitted the PUSCHson UCG cells and according to a hypothesis that the UE did not transmitPUSCHs on UCG cells. When TBCC with CRC is used for encoding theHARQ-ACK codebook, this hypothesis testing is sufficient for the eNB todetermine the HARQ-ACK codebook size. When Reed-Muller coding is usedfor encoding the HARQ-ACK codebook, the eNB cannot determine theHARQ-ACK codebook size as the eNB has no means to determine whether theHARQ-ACK codebook is one that corresponds to a HARQ-ACK codebook fornon-UCG cells or one that corresponds to a HARQ-ACK codebook for bothnon-UCG cells and UCG cells. One approach to resolve this problem is forthe eNB to configure the UE to use of TBCC encoding with CRC attachmentfor a HARQ-ACK codebook when the eNB configures a UCG to the UE. Anotherapproach is for the UE to use OCC {1, −1} for the DMRS per slot of PUCCHFormat 3 when the UE transmits a HARQ-ACK codebook for both non-UCGcells and UCG cells and use OCC {1, 1} when the UE transmits a HARQ-ACKcodebook only for non-UCG cells.

When a UE fails a CCA check and does not transmit a PUSCH with amultiplexed HARQ-ACK codebook on a UCG cell in a SF, the UE typicallydoes not have sufficient time to multiplex the HARQ-ACK codebook onanother channel the UE is scheduled to transmit in the SF. In a firstapproach, the UE can drop the transmission of a HARQ-ACK codebook forUCG cells in the SF. In a second approach, the UE can generate twoversions for a PUCCH or PUSCH transmission, a first version thatincludes HARQ-ACK for UCG cells and a second version that does not, andtransmit either the first version when the CCA fails or the secondversion when the CCA does not fail (and the UE transmits the HARQ-ACKcodebook for UCG cells in a PUSCH on a UCG cell). In a third approach,the UE can transmit the HARQ-ACK codebook for UCG cells in a later SF.

For the third approach, the UE can transmit the HARQ-ACK codebook eitherin a PUSCH on a UCG cell or in a PUCCH or in a PUSCH on a non-UCG cell.In the following, it is assumed that the UE encodes the HARQ-ACKcodebook using TBCC with CRC.

In a first case, the UE transmits a PUSCH in a SF on a UCG cell. Whenthe UE has new HARQ-ACK information to multiplex in the SF, the UEencodes in a same HARQ-ACK codebook both the new HARQ-ACK informationand the HARQ-ACK information the UE had to transmit in a previous SF;otherwise, when the UE does not have new HARQ-ACK information tomultiplex in the SF, the UE encodes in a HARQ-ACK codebook the HARQ-ACKinformation the UE had to transmit in a previous SF and the UEmultiplexes the HARQ-ACK codebook in the PUSCH. The multiplexing of theHARQ-ACK codebook the UE had to transmit in a previous SF can be adefault action by the UE and can be expected by the eNB or, as it willbe subsequently described, can be requested by the eNB for example byincluding a new field, HARQ-ACK_request in an UL DCI format toexplicitly request a transmission from the UE of a HARQ-ACK codeword theUE had to transmit in a previous SF.

When it is a default action by a UE to multiplex in a PUSCH transmissionin a SF a HARQ-ACK codeword the UE had to transmit in a previous SF, theprevious SF can be up to the last SF prior to the SF of the PUSCHtransmission. When an eNB can reliably detect a PUSCH DTX in theprevious SF due to a CCA failure by the UE, the eNB knows that the UEincludes in the PUSCH transmission in the SF the HARQ-ACK codebook theUE had to but was not able to transmit in the previous SF. When the eNBcannot reliably detect a PUSCH DTX in the previous SF due to a CCAfailure by the UE for transmitting the PUSCH in the previous SF, onehypothesis by the eNB can be that a failed CRC check for a presumedreceived HARQ-ACK codeword in the previous SF was due to a CCA failureby the UE. This can be further conditioned on a failed CRC check for thedata TB. The eNB can then decode the PUSCH in the SF according to afirst hypothesis that there is a HARQ-ACK codebook and includes aHARQ-ACK codebook the UE had to transmit in the previous SF in additionto a HARQ-ACK codebook, when any, the UE has to transmit in the SF, andaccording to a second hypothesis that the HARQ-ACK codebook includesonly HARQ-ACK information, when any, the UE has to transmit in the SF.This implies that the eNB performs two decoding operations for a data TBin the PUSCH; one decoding operation according to a first RE mapping fora hypothesis that the UE multiplexes a HARQ-ACK codebook the UE had totransmit in the previous SF, and one decoding operation according to asecond RE mapping for a hypothesis that the UE does not multiplex aHARQ-ACK codebook the UE had to transmit in the previous SF.

To enable an eNB to avoid having to perform two decoding operations fora data TB in a PUSCH transmission from a UE, depending on whether or notthe UE multiplexes in the PUSCH a HARQ-ACK codebook the UE had totransmit in a previous SF, the UE can separately encode and transmitinformation about the HARQ-ACK codebook in a SF. For example, using a1-bit field that is separately transmitted from a HARQ-ACK codebook in aSF, the UE can indicate whether or not the UE multiplexes a HARQ-ACKcodebook the UE had to transmit in a previous SF in the PUSCHtransmission in the SF. This is similar to the UE transmitting aPUSCH_Tx_ind as it was previously described.

UCI Transmission in Multiple PUSCHs or PUCCHs

For brevity, the following descriptions are with respect to HARQ-ACKinformation but they are also directly applicable to A-CSI. When a UEneeds to perform CCA before transmitting a PUSCH, or a PUCCH when itexists on a UCG cell, and when the UE is scheduled by an eNB formultiple PUSCH transmissions on respective multiple cells in a SF, theUE can multiplex a HARQ-ACK codebook in more than one PUSCHtransmissions in the SF in order to improve a probability fortransmission of the HARQ-ACK codebook. A number of PUSCH transmissionsin a SF for a UE to multiplex a HARQ-ACK codebook can be configured tothe UE by an eNB or can include all PUSCH transmission from the UE inthe SF. Similar, in case a UE is scheduled for PUSCH transmissions overmultiple respective SFs on a cell, the UE can multiplex a HARQ-ACKcodebook in each of the multiple PUSCH transmissions in order to improvea probability that a CCA succeeds in at least one of the multiple SFsand the UE transmits the PUSCH with the multiplexed HARQ-ACK codebook.Moreover, in case a UE has different HARQ-ACK codebooks to transmit indifferent SFs, the UE can jointly encode the HARQ-ACK codebooks the UEhad to transmit in earlier SFs with a HARQ-ACK codebook, when any, in alater SF for transmission in the later SF in case the UE failed CCAtests in the respective earlier SFs.

To reduce an overhead associated with replicating multiplexing of aHARQ-ACK codebook over multiple PUSCH transmission either acrossmultiple cells in a same SF or across multiple SFs or across bothmultiple cells and multiple SFs, or both, an eNB can configure a UEdifferent β_(PUSCH) ^(HARQACK) values (also described in REF 2 and REF3) for use when the UE multiplexes a HARQ-ACK codebook in a respectivedifferent number of PUSCH transmissions. For example, the eNB canconfigure a first β_(PUSCH) ^(HARQACK) value for use when the UE isscheduled to multiplex a HARQ-ACK codebook in one PUSCH transmission andconfigure a second β_(PUSCH) ^(HARQACK) value when the UE is scheduledto multiplex the HARQ-ACK codebook in more than one PUSCH transmission.The eNB can configure a set of β_(PUSCH) ^(HARQACK) values and indicateto the UE one β_(PUSCH) ^(HARQACK) value from the set of β_(PUSCH)^(HARQACK) values through a field in an UL DCI format scheduling a PUSCHtransmission. For example, the eNB can configure a UE with two β_(PUSCH)^(HARQACK) values and use a field that includes one binary element in anDCI format scheduling a PUSCH transmission to indicate use of a firstβ_(PUSCH) ^(HARQACK) value when the UE is scheduled to multiplex aHARQ-ACK codebook in one PUSCH transmission and indicate use of a secondβ_(PUSCH) ^(HARQACK) value when the UE is scheduled to multiplex theHARQ-ACK codebook in more than one PUSCH transmissions. For example,when an eNB schedules a single PUSCH transmission to a UE, the eNB canindicate a maximum β_(PUSCH) ^(HARQACK) value from a set of configuredβ_(PUSCH) ^(HARQACK) values while when the eNB schedules three PUSCHtransmissions to the UE, the eNB can indicate a β_(PUSCH) ^(HARQACK)value that can result to a target HARQ-ACK codeword BLER when the UEtransmits at least two from the three scheduled PUSCH transmissions.

FIG. 30 illustrates a use of a β_(PUSCH) ^(HARQACK) value fordetermining resources for multiplexing a HARQ-ACK codebook in a numberof scheduled PUSCH transmissions depending on the number of scheduledPUSCH transmission according to this disclosure. The embodiment shown inFIG. 30 is for illustration only. Other embodiments could be usedwithout departing from the scope of the present disclosure.

Dropped Transmission of HARQ-ACK Codebook or Erroneously DetectedHARQ-ACK Codebook

An eNB cannot be generally assumed to be able to detect an absence of aPUSCH transmission on a UCG cell, especially with accuracy of 99% orbetter, at least because there can be a transmission from anotherdevice, including an LTE UE associated with a different operator, on theUCG cell. Consequences from an inability of a UE to transmit a PUSCHwith multiplexed HARQ-ACK codebook on a UCG cell due a CCA failure canvary depending on a coding method for the HARQ-ACK codebook. When TBCCwith CRC is used for encoding the HARQ-ACK codebook, the CRC check isexpected to fail as no HARQ-ACK codebook is transmitted. Then, aconsequence is that the eNB retransmits all associated PDCCHs/PDSCHs.When a Reed-Muller code is used for HARQ-ACK encoding, a consequence canbe more damaging as there is no CRC protection and the eNB can makeseveral HARQ-ACK errors leading to dropped data TBs, for example when aNACK is interpreted as ACK, and requiring higher layer ARQ assistance.When repetition coding is used for HARQ-ACK encoding, the eNB can inprinciple detect an absence of a HARQ-ACK codebook. Therefore, aconsequence from a CCA failure for a PUSCH transmission is at least a DLthroughput loss due to PDCCH retransmissions and PDSCH retransmissionsfor the data TBs that the UE failed to provide a HARQ-ACK codebook.

To enable an eNB avoid unnecessary retransmissions of PDCCHs and PDSCHsdue to a UE inability to transmit a PUSCH with a multiplexed HARQ-ACKcodebook, the UE can transmit information, referred to as PUSCH_Tx_ind,to indicate whether or not the UE transmits PUSCH in a SF and assist theeNB in determining a presence or absence of a PUSCH transmission. APUSCH_Tx_ind transmission can be further conditioned on a UE detectingan UL DCI format scheduling a PUSCH transmission on a UCG cell.

In a first approach, a PUSCH_Tx_ind is a sequence of binary elementsthat a UE multiplexes in a PUSCH transmission. A length of the sequencecan be determined in a same manner as a number of REs used to multiplexa HARQ-ACK codebook of one binary element in a PUSCH based on an offsetβ_(PUSCH) ^(IND) that an eNB configures to the UE and based on the MCSfor the data TB. The sequence can be a series of 1 values or −1 values,similar to a UE transmitting a NACK or an ACK, respectively, or a seriesof alternating 1 values and −1 values on, in general, a predefinedpattern of 1 s and −1 s. The eNB can determine whether or not the UEtransmits a PUSCH in a SF by determining whether or not the UE transmitsa PUSCH_Tx_ind for example by the eNB determining whether or not the eNBdetects a respective sequence pattern. When a UE does not transmit aPUSCH in a SF and other devices transmit in PUSCH resources in the SF,the length of the PUSCH_Tx_ind sequence can be configured to be longenough so that a probability for incorrectly determining presence orabsence of the sequence is sufficiently small such as below 0.01. Thefirst approach is particularly applicable when a UE does not multiplex aHARQ-ACK codebook in a PUSCH.

FIG. 31 illustrates a multiplexing of a PUSCH_Tx_ind in a PUSCHtransmission according to this disclosure. The embodiment shown in FIG.31 is for illustration only. Other embodiments could be used withoutdeparting from the scope of the present disclosure.

A UE multiplexes a PUSCH_Tx_ind information in a PUSCH 3110. The UEtransmits the PUSCH in a SF 3120. The PUSCH_Tx_ind information is abinary element indicating whether or not the UE was able to transmit aPUSCH on a UCG cell in a previous SF. The multiplexing of thePUSCH_Tx_ind information can be conditioned on the UE having amultiplexed HARQ-ACK codeword in the PUSCH transmission in the previousSF. The eNB detects whether or not the UE transmits the PUSCH_Tx_ind inthe SF (and the eNB can implicitly determine whether or not the UEsucceeded a CCA) and from the PUSCH_Tx_ind the eNB can determine whetheror not the UE transmitted a PUSCH in the previous SF 3130.

In a second approach, when a UE multiplexes a HARQ-ACK codeword in aPUSCH or in a PUCCH, the UE includes a PUSCH_Tx_ind information of oneor more bits in a HARQ-ACK codebook together with HARQ-ACK information,for example before or after the HARQ-ACK information. As for the firstapproach, the PUSCH_Tx_ind indicates a number of previous PUSCHtransmissions with a multiplexed HARQ-ACK codeword that the UE had todrop due to a CCA failure. For example, the PUSCH_Tx_ind can include 1or 2 binary elements where, in case of 2 binary elements, a mapping fora first value (‘00’) can indicate there was no PUSCH transmission with amultiplexed HARQ-ACK codeword that was dropped in the previous 3scheduled PUSCH transmissions with a multiplexed HARQ-ACK codeword, anda mapping for the second, third, and fourth values (‘01’, ‘10’, and ‘11’respectively) can indicate there were 1, 2, and 3 PUSCH transmissionswith a multiplexed HARQ-ACK codeword that the UE dropped prior totransmitting the current HARQ-ACK codeword.

FIG. 32 illustrates a multiplexing of a PUSCH_Tx_ind with HARQ-ACKinformation in a HARQ-ACK codebook according to this disclosure. Theembodiment shown in FIG. 32 is for illustration only. Other embodimentscould be used without departing from the scope of the presentdisclosure.

A UE jointly encodes HARQ-ACK information and a PUSCH_Tx_ind 3210. TheUE transmits the HARQ-ACK and PUSCH_Tx_ind codebook 3220. Thetransmission can be in a PUSCH or in a PUCCH. The eNB detects theHARQ-ACK and PUSCH_Tx_ind codebook and can determine whether or not theUE transmitted a PUSCH in the previous SF when the detection is correct3230.

In a third approach, when an eNB fails to detect a HARQ-ACK codebooktransmitted from a UE, as the eNB determines based on a failed CRC checkfor a HARQ-ACK codebook that the eNB assumes to receive, the eNB canschedule in a SF the UE to retransmit the HARQ-ACK codebook. Thescheduling can be by a DCI format that can have a same size as a DL DCIformat or an UL DCI format that the UE decodes in the SF. The DCI formatcan further include an explicit HARQ-ACK request field or a reservedcode-point in the DCI format can serve to indicate an HARQ-ACK request.For example, for an UL DCI format, a value for the CS and OCC field fora DMRS, such as the ‘111’ value, can be reserved to instead indicate aHARQ-ACK request. In a first realization, a UE can determine a HARQ-ACKcodebook to transmit due to a detection of HARQ-ACK request from aunique time relationship to a SF where the UE detects a DCI formatconveying the HARQ-ACK request. For example, when the UE detects the DCIformat with HARQ-ACK request in SF n, the UE transmits a HARQ-ACKcodebook that the UE was scheduled to transmit (or that the UEtransmitted) in a first SF prior to, for example, SF n−3. In a secondrealization, a UE can determine a HARQ-ACK codebook to transmit due to adetection of HARQ-ACK request in a DCI format the UE detects from afield in the DCI format that explicitly indicates a SF from a number ofprevious SFs where the UE was scheduled to transmit (or transmitted) theHARQ-ACK codebook. For example, a 4-bit field in a DCI format a UEdetects in SF n can indicate one of 16 previous SFs starting from apredetermined SF such as, for example, SF n−2. For example, a 4-bitfield in a DCI format a UE detects in SF n can be a bit-map indicatingup to 4 of the previous 4 SFs starting from a predetermined SF such as,for example, subframe n−2, where the UE was schedule to transmit (ortransmitted) a HARQ-ACK codebook. In case the DCI format schedules onlytransmission of a HARQ-ACK codebook, the 4-bit field can use sameelements as a HARQ process number of 4 bits that indicates a HARQprocess number in case the DCI format schedules a PUSCH transmission.When a UE is scheduled to multiplex a first HARQ-ACK codebook in a PUSCHtransmission or a PUCCH transmission and the UE also detects a DCIformat with a HARQ-ACK request for a previous second HARQ-ACK codebook,the UE can jointly encode the first and second HARQ-ACK codebooks andtransmit the encoded joined HARQ-ACK codebook. Alternatively, at leastwhen a size of a joint HARQ-ACK codebook is larger than a predeterminedthreshold, the UE can separately encode the first HARQ-ACK codebook andthe second HARQ-ACK codebook.

FIG. 33 illustrates a transmission of a HARQ-ACK codebook by a UE inresponse to a detection of a DCI format conveying a HARQ-ACK requestaccording to this disclosure. The embodiment shown in FIG. 33 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

A UE detects a DCI format conveying a HARQ-ACK request in SF n 3310.Based either on a predetermined timing relative to SF n or on anexplicit indication in the DCI format, the UE determines a HARQ-ACKcodebook to transmit in a PUSCH or PUCCH with transmission parametersscheduled by the DCI format 3320. The UE transmits the PUSCH or thePUCCH including the HARQ-ACK codebook 3330.

FIG. 34 illustrates an example timeline for a transmission of a HARQ-ACKcodebook by a UE according to this disclosure. The embodiment shown inFIG. 34 is for illustration only. Other embodiments could be usedwithout departing from the scope of the present disclosure.

A UE is scheduled to transmit a HARQ-ACK codebook to an eNB in a firstSF on a cell. The UE fails a CCA test and drops the transmission of theHARQ-ACK codebook 3410. The eNB determines an incorrect reception or anabsence of reception for the HARQ-ACK codebook and transmits a DCIformat to the UE that includes a HARQ-ACK request and the UE detects theDCI format in a second SF on a same cell or on a different cell 3420.The UE transmits the HARQ-ACK codebook to the eNB in a third SF in aPUSCH or in a PUCCH 3430. Although the first, second, and third SFs areshown to be separated by four SFs, this is only for illustrativepurposes and other time separation for the three SFs can also apply, forexample depending on an availability for a respective cell.

In a fourth approach, similar to the third approach, a HARQ-ACK codewordtransmission is triggered by a DCI format, but the DCI format indicatesHARQ-ACK information the UE generates for a number of SFs and not onlyfor a single DL SF. For a number of HARQ processes, such as 16 HARQprocesses, and for a number of cells where the UE is configured toreceive PDSCH transmissions, such as 20 cells, the DCI format canindicate to the UE to report HARQ-ACK information for a subset of theHARQ processes or for a subset of cells. The fourth approach isbeneficial for reducing a number of PUSCH transmissions required toconvey HARQ-ACK information, as a PUSCH transmission does not need to bescheduled in each SF, and HARQ-ACK information for several SFs can beincluded in a HARQ-ACK codeword transmitted in a single PUSCH. Thefourth approach is also beneficial for controlling a number of HARQ-ACKinformation bits transmitted in a PUSCH and in this manner ensure thatcoverage can be provided for a particular UE. It can also enabletransmission of HARQ-ACK information that was incorrectly received in aprevious SF, with new HARQ-ACK information as it was also described forthe third approach. This largely removes a requirement from an eNB todetermine whether or not a UE actually transmitted a PUSCH conveying theHARQ-ACK codeword as the outcome of incorrect HARQ-ACK codeworddetection (as determined from an incorrect CRC check) is same in bothcases.

For example, a field that includes 2 bits in a DCI format can indicateto the UE to transmit a HARQ-ACK codeword in a PUSCH that includesHARQ-ACK information for the first four HARQ process when a binary valuefor the field is ‘00’, and for the second, third, or fourth four HARQprocesses when a binary value for the field is respectively ‘01, ‘10’,or ‘11’. For example, a field that includes 3 bits in a DCI format canindicate to the UE to transmit a HARQ-ACK codeword in a PUSCH thatincludes HARQ-ACK information for the first, second, third, or fourth,four HARQ process when a binary value for the field is respectively‘000’, ‘001’, ‘010’, and ‘011’, or that includes HARQ-ACK informationfor the first and second, first and third, first and fourth, second andthird, second and fourth, or third and fourth, four HARQ process when abinary value for the field is respectively ‘100’, ‘101’, ‘110’, and‘111’.

For example, the cells can be divided by a configuration from an eNBinto a number of groups, such as four cell groups that include thefirst, second, third, or fourth 5 cells from the 20 cells, respectively,and a DCI format transmitted to a UE can include a field indicatinggroups of cells for the UE to report HARQ-ACK information in a PUSCHtransmission. For example, a field that includes 2 bits can indicate thefirst, second, third, or fourth group of cells using respective valuesof ‘00’, ‘01’, ‘10’, and ‘11’ or a field that includes 3 bits canindicate the first, second, third, fourth, first and second, first andthird, first and fourth, second and third, second and fourth, or thirdand fourth groups of cells using respective values of ‘000’, ‘001’,‘010’, ‘011’, ‘100’, ‘101’, ‘110’, ‘111’.

In case of multi-SF PUSCH scheduling, a field in a respective DCI formatcan indicate to a UE a HARQ-ACK codeword to be transmitted in a firstSF. The UE can transmit in remaining SFs additional HARQ-ACK codewordsin a predetermined order. For example, in case the DCI format indicatestransmission of HARQ-ACK information for the second four HARQ processesin a PUSCH and schedules PUSCH transmissions over four SFs, the UEtransmits HARQ-ACK information for the second, third, fourth, and firstHARQ processes in the first, second, third, and fourth SFs,respectively. For example, in case a UE is scheduled PUSCH transmissionsover two SFs and is triggered transmission of HARQ-ACK information, theUE can multiplex HARQ-ACK information for a first group of cells in atransmission in a first SF and multiplex HARQ-ACK information for asecond group of cells in a transmission in a second SF.

To aid the Patent Office and any readers of any patent issued on thisapplication in interpreting the claims appended hereto, applicants wishto note that they do not intend any of the appended claims or claimelements to invoke 35 U.S.C. § 112(f) unless the words “means for” or“step for” are explicitly used in the particular claim. Use of any otherterm, including without limitation “mechanism,” “module,” “device,”“unit,” “component,” “element,” “member,” “apparatus,” “machine,”“system,” “processor,” or “controller,” within a claim is understood bythe applicants to refer to structures known to those skilled in therelevant art and is not intended to invoke 35 U.S.C. § 112(f).

Although the present disclosure has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

What is claimed:
 1. A user equipment (UE), comprising: a receiverconfigured to receive: a physical downlink control channel (PDCCH),wherein: the PDCCH provides a downlink control information (DCI) format,and the DCI format schedules transmission of n_(puscH)≥1 physical uplinkshared channels (PUSCHs) up to a maximum of N_(PUSCH) PUSCHtransmissions; a decoder configured to decode the DCI format, whereinthe DCI format includes: a hybrid automatic repeat request (HARQ)process number field that indicates a HARQ process number n_(HARQ) froma maximum of N_(HARQ) HARQ process numbers, wherein, the HARQ processnumber n_(HARQ) applies for a first PUSCH transmission, and whenn_(PUSCH)>1, a HARQ process number (n_(HARQ)+j−1)mod N_(HARQ) appliesfor a j-th PUSCH transmission, wherein 1<j≤n_(HARQ), a redundancyversion (RV) field, wherein when n_(PUSCH)=1, the RV field includes twobits for the PUSCH transmission, and when n_(PUSCH)>1, the RV fieldincludes one bit for each of the PUSCH transmissions, and a new dataindicator (NDI) field that includes one bit for each of the n_(PUSCH)PUSCH transmissions; and a transmitter configured to transmit then_(PUSCH) PUSCHs.
 2. The UE of claim 1, wherein: when n_(PUSCH)>1, theRV field includes a total of N_(PUSCH) bits, and the NDI field includesa total of N_(PUSCH) bits.
 3. The UE of claim 1, wherein: when the RVfield includes two bits, the RV field value is one of 0, 1, 2, and 3,and when the RV field includes one bit, the RV field value is one of 0and
 2. 4. The UE of claim 1, wherein: a PUSCH transmission is over amaximum number of M_(I), interlaces, wherein an interlace: has an indexm_(I), 0≤m_(I)<M_(I), and includes a number of equidistantnon-contiguous resource blocks of a bandwidth, and the DCI formatincludes a resource allocation field of ┌log₂(M_(I)·(M_(I)+1)/2)┐ bitsthat assigns to a PUSCH transmission one of: a number of consecutiveinterlace indexes, and a combination of interlace indexes from apredetermined set of combinations of interlace indexes, wherein ┌ ┐ is aceiling function that rounds a number to its immediately next largerinteger.
 5. The UE of claim 1, wherein: the DCI format includes atransmission power control (TPC) command field that provides a PUSCHtransmission power adjustment, n_(PUSCH)>1, and the PUSCH transmissionpower adjustment applies to all n_(puscH) PUSCH transmissions.
 6. The UEof claim 1, wherein the DCI format includes a field indicating a timeoffset between a time of the PDCCH reception and a time of the firstPUSCH transmission.
 7. The UE of claim 1, wherein: the DCI formatincludes a field triggering a channel state information (CSI) report,the DCI format schedules transmission of n_(puscH)=2 PUSCHs, and thetransmitter is further configured to transmit the CSI report in a secondPUSCH.
 8. A base station, comprising: a transmitter configured totransmit: a physical downlink control channel (PDCCH), wherein: thePDCCH provides a downlink control information (DCI) format, and the DCIformat schedules reception of n_(PUSCH)≥1 physical uplink sharedchannels (PUSCHs) up to a maximum of N_(PUSCH) PUSCH receptions; anencoder configured to encode the DCI format, wherein the DCI formatincludes: a hybrid automatic repeat request (HARQ) process number fieldthat indicates a HARQ process number n_(HARQ) from a maximum of N_(HARQ)HARQ process numbers, wherein, the HARQ process number n_(HARQ) appliesfor a first PUSCH reception, and when n_(PUSCH)>1, a HARQ process number(n_(HARQ)+j−1)mod N_(HARQ) applies for a j-th PUSCH reception, wherein1<j≤n_(HARQ), a redundancy version (RV) field, wherein when n_(PUSCH)=1,the RV field includes two bits for the PUSCH reception, and whenn_(PUSCH)>1, the RV field includes one bit for each of the PUSCHreceptions, and a new data indicator (NDI) field that includes one bitfor each of the n_(PUSCH) PUSCH receptions; and a receiver configured toreceive the n_(PUSCH) PUSCHs.
 9. The base station of claim 8, wherein:when n_(PUSCH)>1, the RV field includes a total of N_(PUSCH) bits, andthe NDI field includes a total of N_(PUSCH) bits.
 10. The base stationof claim 8, wherein: when the RV field includes two bits, the RV fieldvalue is one of 0, 1, 2, and 3, and when the RV field includes one bit,the RV field value is one of 0 and
 2. 11. The base station of claim 8,wherein: a PUSCH reception is over a maximum number of M_(I),interlaces, wherein an interlace: has an index m_(i), 0≤m_(i)<M_(i), andincludes a number of equidistant non-contiguous resource blocks of abandwidth, and the DCI format includes a resource allocation field of┌log₂(M_(I)·(M_(I)+1)/2)┐ bits that assigns to a PUSCH reception one of:a number of consecutive interlace indexes, and a combination ofinterlace indexes from a predetermined set of combinations of interlaceindexes, wherein ┌ ┐ is a ceiling function that rounds a number to itsimmediately next larger integer.
 12. The base station of claim 8,wherein the DCI format includes a field indicating a time offset betweena time of the PDCCH transmission and a time of the first PUSCHreception.
 13. The base station of claim 8, wherein: the DCI formatincludes a field triggering a channel state information (CSI) report,the DCI format schedules reception of n_(PUSCH)=2 PUSCHs, and thereceiver is further configured to receive the CSI report in a secondPUSCH.
 14. A method for transmitting one or more physical uplink sharedchannels (PUSCHs), the method comprising: receiving: a physical downlinkcontrol channel (PDCCH), wherein: the PDCCH provides a downlink controlinformation (DCI) format, and the DCI format schedules transmission ofn_(PUSCH)1 PUSCHs up to a maximum of N_(PUSCH) PUSCH transmissions;decoding the DCI format, wherein the DCI format includes: a hybridautomatic repeat request (HARQ) process number field that indicates aHARQ process number n_(HARQ) from a maximum of N_(HARQ) HARQ processnumbers, wherein, the HARQ process number n_(HARQ) applies for a firstPUSCH transmission, and when n_(puscH)>1, a HARQ process number(n_(HARQ)+j−1)mod N_(HARQ) applies for a j-th PUSCH transmission,wherein 1<j≤n_(HARQ), a redundancy version (RV) field, wherein whenn_(PUSCH)=1, the RV field includes two bits for the PUSCH transmission,and when n_(PUSCH)>1, the RV field includes one bit for each of thePUSCH transmissions, and a new data indicator (NDI) field that includesone bit for each of the n_(puscH) PUSCH transmissions; and transmittingthe n_(PUSCH) PUSCHs.
 15. The method of claim 14, wherein: whenn_(PUSCH)>1, the RV field includes a total of N_(PUSCH) bits, and theNDI field includes a total of N_(PUSCH) bits.
 16. The method of claim14, wherein: when the RV field includes two bits, the RV field value isone of 0, 1, 2, and 3, and when the RV field includes one bit, the RVfield value is one of 0 and
 2. 17. The method of claim 14, wherein: aPUSCH transmission is over a maximum number of M_(I), interlaces,wherein an interlace: has an index m_(I), 0≤m_(I)<M_(I), and includes anumber of equidistant non-contiguous resource blocks of a bandwidth, andthe DCI format includes a resource allocation field of┌log₂(M_(I)·(M_(I)+1)/2)┐ bits that assigns to a PUSCH transmission oneof: a number of consecutive interlace indexes, and a combination ofinterlace indexes from a predetermined set of combinations of interlaceindexes, wherein ┌ ┐ is a ceiling function that rounds a number to itsimmediately next larger integer.
 18. The method of claim 14, wherein:the DCI format includes a transmission power control (TPC) command fieldthat provides a PUSCH transmission power adjustment, n_(PUSCH)>1, andthe PUSCH transmission power adjustment applies to all n_(PUSCH) PUSCHtransmissions.
 19. The method of claim 14, wherein the DCI formatincludes a field indicating a time offset between a time of the PDCCHreception and a time of the first PUSCH transmission.
 20. The method ofclaim 14, wherein: the DCI format includes a field triggering a channelstate information (CSI) report, the DCI format schedules transmission ofn_(PUSCH)=2 PUSCHs, and transmitting the CSI report in a second PUSCH.